Kidney function, medication dosing, UV exposure, and health screening calculators. Browse our free general health tools below — all calculators are instant, accurate, and require no sign-up.
20/20 Vision Calculator — Convert Snellen visual acuity to LogMAR, decimal, and MAR. Check driving eligibility and compare vision classification across international standards.
6-Minute Walk Test Calculator — Calculate 6MWT predicted distance using Enright equations. Evaluate percent predicted, NYHA class, oxygen desaturation, chronotropic index, and DSP.
A-a Gradient Calculator — Calculate the alveolar-arterial oxygen gradient from ABG values. Includes P/F ratio, expected gradient by age, altitude adjustment, and differential diagnosis table.
Ankle-Brachial Index Calculator — Calculate the ankle-brachial index (ABI) for PAD screening. Interprets severity, flags non-compressible arteries, inter-arm differences, and Rutherford classification.
ACFT Score Calculator — Calculate Army Combat Fitness Test scores across all 6 events. Includes pass/fail by physical demand category, score breakdown, and training recommendations.
Acid-Base Disorder Calculator — Interpret ABG results with step-by-step acid-base analysis. Calculates anion gap, delta-delta ratio, Winter's formula, and identifies primary and mixed disorders.
Albumin-to-Creatinine Ratio Calculator — Calculate urine albumin-to-creatinine ratio (ACR) with KDIGO staging. Classifies microalbuminuria, macroalbuminuria, and CKD prognosis by GFR and albuminuria.
Addiction Screening Calculator — CAGE and DAST-10 substance use screening questionnaires. Scores, interprets severity, and provides recommended actions for alcohol and drug use assessment.
Adrenal CT Washout Calculator — Calculate absolute and relative percentage washout for adrenal masses. Differentiates adenoma from metastasis/carcinoma with contrast enhancement curves.
Ankle Fracture Treatment Calculator — Ottawa ankle rules, Weber classification, and stability assessment for ankle fractures. Evaluates medial clear space, syndesmosis, talar tilt, and treatment decisions.
AHI (Apnea-Hypopnea Index) Calculator — Calculate your Apnea-Hypopnea Index from sleep study data. Includes supine AHI, REM AHI, positional analysis, severity grading, and treatment recommendations.
Air Force PT Test Score Calculator — Calculate your USAF Physical Fitness Assessment score. Includes 1.5-mile run, push-ups, sit-ups, pull-ups/plank with age and gender-adjusted scoring tables.
Alcohol BAC Estimator Calculator — Estimate your Blood Alcohol Concentration (BAC) using the Widmark formula. See how long until your BAC returns to zero and understand impairment levels.
Alcohol Units Calculator — Convert drinks to UK units, US standard drinks, and Australian standard drinks. Calculates alcohol grams, calories, estimated BAC, and weekly risk assessment.
ANC (Absolute Neutrophil Count) Calculator — Calculate your absolute neutrophil count from CBC with differential. Includes ALC, AMC, AEC, severity grading, febrile neutropenia risk, and causes of neutropenia.
Alzheimer's Life Expectancy Calculator — Estimate survival and disease progression in Alzheimer's disease based on stage, age, MMSE, comorbidities, and functional status. Includes stage duration and risk factor tables.
ANC Calculator (Without Bands) — Calculate absolute neutrophil count when bands are not reported. Includes NLR (neutrophil-to-lymphocyte ratio), all absolute counts, severity grading, and percentage or absolute input modes.
Anion Gap Calculator — Calculate serum anion gap and albumin-corrected anion gap. Differentiate metabolic acidosis causes with clinical interpretation.
APFT (Army Physical Fitness Test) Score Calculator — Calculate your APFT score with push-ups, sit-ups, and 2-mile run. Age and gender-adjusted scoring with minimum standards, promotion points, and fitness category.
APRI Score Calculator (AST to Platelet Ratio Index) — Calculate the APRI score for non-invasive liver fibrosis assessment. Also computes FIB-4 index and De Ritis ratio with fibrosis staging and treatment guidance.
Arterial (Vascular) Age Calculator — Estimate your arterial age based on cardiovascular risk factors. Compare vascular age to chronological age with modifiable risk reduction recommendations.
AST:ALT Ratio (De Ritis Ratio) Calculator — Calculate the AST to ALT ratio (De Ritis ratio) and R factor for liver disease pattern analysis. Differential diagnosis tables for alcoholic, viral, and metabolic liver disease.
AUDIT-10 (Full AUDIT) Alcohol Assessment Calculator — Complete AUDIT-10 alcohol use disorder screening tool. All 10 WHO questions with zone scoring, 3-domain breakdown, AUD severity estimation, and evidence-based intervention guide.
AUDIT-C Alcohol Screening Calculator — Calculate your AUDIT-C score for alcohol use screening. 3-question validated tool with sex-specific thresholds, sensitivity data, and clinical intervention recommendations.
Baby's Milk Intake Calculator — Calculate recommended daily and per-feed milk intake for babies 0-12 months by weight and age. Covers formula and breast milk with growth spurt timing and feeding guidelines.
Baby Eye Color Predictor Calculator — Predict your baby's eye color probability from parent and grandparent eye colors. Simplified Mendelian genetics model with probability bars, color charts, and eye color facts.
BAC (Blood Alcohol Content) Calculator — Estimate your blood alcohol content using the Widmark formula. Factors in sex, weight, drinks, time, and stomach contents with impairment levels and legal limits worldwide.
Back to Normal Life (Surgery Recovery) Calculator — Estimate your personalized surgery recovery timeline adjusted for age, fitness, BMI, smoking, diabetes, and complications. Activity milestones for desk work, driving, exercise, and full recovery.
BAI (Body Adiposity Index) Calculator — Calculate your Body Adiposity Index from hip circumference and height. Estimates body fat percentage without a scale, with sex-specific categories and comparison to BMI.
BBT (Basal Body Temperature) Calculator — Track your basal body temperature for fertility awareness. Estimates ovulation day, cycle phase, fertility window, thermal shift detection with the 3-over-6 rule, and cycle timeline visualization.
Bed Size Calculator — Find the right bed size for your room, height, and number of sleepers. Calculates per-person width, height clearance, room coverage, walking space, and sheet sizes.
BEE / BMR (Basal Energy Expenditure) Calculator — Calculate your Basal Metabolic Rate using Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle formulas. Estimates TDEE, macro targets, and weight management calorie levels.
Benzodiazepine Conversion & Equivalence Calculator — Convert between benzodiazepine doses using diazepam equivalents. Full equivalence table for 12 benzodiazepines with half-life, onset, duration, and Ashton Manual taper guidance.
BIMS (Brief Interview for Mental Status) Calculator — Score the BIMS cognitive screening from the MDS 3.0. Tests repetition, temporal orientation, and recall with interpretation thresholds for intact, moderate, and severe impairment.
Berg Balance Scale (BBS) Calculator — Score the 14-item Berg Balance Scale for fall risk assessment in older adults. Visual breakdown per task, fall risk thresholds, and minimal clinically important difference guidance.
BMI Amputee Calculator — Calculate adjusted BMI for amputees using body-weight correction factors. Accurate BMI estimation accounting for limb loss with standard amputation percentages.
Bladder Volume Calculator — Estimate urinary bladder volume from ultrasound dimensions using the ellipsoid formula. Includes post-void residual interpretation, age-based capacity norms, and measurement method comparison.
Breast Cancer Risk Calculator (Gail Model) — Estimate 5-year and lifetime breast cancer risk using Gail Model factors: age, menarche, first birth, family history, biopsies, and atypical hyperplasia. Includes chemoprevention and screening guid...
Breast Cancer Recurrence Risk Calculator — Estimate breast cancer 5-year and 10-year recurrence risk from tumor size, grade, lymph nodes, ER/HER2/Ki-67 status. Includes molecular subtype classification and genomic assay guide.
Caffeine Calculator — Calculate total caffeine intake from multiple sources, track metabolic decay with half-life modeling, check daily limits, and estimate time until sleep-safe levels. 20+ drink database included.
Body Roundness Index (BRI) Calculator — Calculate the Body Roundness Index from waist circumference and height. Compares BRI to BMI, WHtR, and ABSI with cardiometabolic risk categories and waist circumference thresholds.
CAGE Questionnaire Calculator — Score the 4-question CAGE alcohol screening questionnaire. Includes interpretation thresholds, SBIRT workflow, and comparison to AUDIT, AUDIT-C, MAST, and other screening tools.
Caffeine Half-Life Calculator — Calculate how much caffeine remains in your body over time. See hourly caffeine decay, find your ideal cutoff time before bed, and understand caffeine metabolism.
Car Heat Calculator — Estimate interior car temperature based on outside temperature, sun exposure, window status, and vehicle color. Includes temperature timeline, heatstroke warning signs, and safety guidance.
Charlson Comorbidity Index (CCI) Calculator — Calculate the Charlson Comorbidity Index with age adjustment from 19 comorbid conditions. Includes survival estimates, condition weights, and organ system breakdown.
Crohn's Disease Activity Index (CDAI) Calculator — Calculate the CDAI score from 8 weighted clinical variables. Includes component breakdown, activity classification, treatment guidance, and clinical trial thresholds.
Cerebral Perfusion Pressure (CPP) Calculator — Calculate CPP from MAP and ICP with tiered management guidance, ICP scenario modeling, pediatric targets, and cerebral autoregulation reference.
Cigarette Cost & Health Impact Calculator — Calculate the financial cost and health impact of smoking. Includes pack-year calculation, life expectancy loss, tar intake, savings projections, and quit-smoking health recovery timeline.
Circadian Rhythm Sleep Phase Calculator — Calculate your ideal sleep-wake schedule, melatonin onset, peak productivity windows, and caffeine cutoff based on chronotype and wake time.
CIWA-Ar Alcohol Withdrawal Assessment Calculator — Calculate the CIWA-Ar score (Clinical Institute Withdrawal Assessment for Alcohol) to assess severity of alcohol withdrawal symptoms and guide treatment.
Corrected Calcium Calculator — Calculate albumin-corrected calcium from measured serum calcium and albumin levels. Detect true hypocalcemia or hypercalcemia in hypoalbuminemic patients.
COVID-19 Event Gathering Risk Calculator — Estimate the probability of COVID-19 exposure at gatherings based on event size, community prevalence, vaccination rates, masking, and ventilation.
COVID-19 Mortality Risk Assessment Calculator — Estimate your COVID-19 infection fatality rate, hospitalization risk, ICU risk, and long COVID probability based on age, vaccination, comorbidities, and BMI.
Colorectal Cancer Screening Risk Calculator — Assess your colorectal cancer risk based on age, family history, lifestyle factors, and comorbidities. Get personalized screening recommendations.
Creatinine Clearance Calculator (Cockcroft-Gault) — Calculate creatinine clearance using the Cockcroft-Gault equation with actual, ideal, and adjusted body weight. Includes CKD staging and drug dosing guidance.
Creatinine Clearance Calculator — Calculate creatinine clearance using the Cockcroft-Gault equation. Estimate kidney function for drug dosing and renal assessment.
Crown-Rump Length Gestational Age Calculator — Calculate gestational age and estimated due date from crown-rump length (CRL) ultrasound measurement using Robinson or Hadlock formulas.
CURB-65 Pneumonia Severity Score Calculator — Calculate the CURB-65 score for community-acquired pneumonia severity assessment. Determine 30-day mortality risk and recommended disposition.
Cardiovascular Disease 10-Year Risk Calculator — Calculate your 10-year risk of cardiovascular disease using the ACC/AHA Pooled Cohort Equations. Get statin recommendations and heart age estimate.
Dual Antiplatelet Therapy Duration Calculator — Calculate optimal DAPT duration after coronary stenting based on bleeding vs. ischemic risk. DAPT score with stent type and OAC considerations.
Denver HIV Risk Score Calculator — Calculate your HIV testing need with the Denver HIV Risk Score. Assess PrEP eligibility, testing frequency, and risk factor analysis for HIV screening.
PHQ-9 Depression Screening Questionnaire Calculator — Screen for depression using the PHQ-9 questionnaire. Score severity, get treatment recommendations, and track symptoms over time with this validated tool.
DLBCL IPI Prognosis Calculator — Calculate the International Prognostic Index (IPI) score for diffuse large B-cell lymphoma. Estimate survival, complete response rates, and risk stratification.
Maddrey Discriminant Function Calculator — Calculate the Maddrey Discriminant Function (MDF) for alcoholic hepatitis severity. Determine steroid eligibility with MELD comparison and treatment algorithm.
Archery Draw Length Calculator — Calculate your archery draw length from wingspan, height, or forearm measurements. Get arrow length, spine recommendations, and bow size guidance.
Dietary Reference Intake (DRI) Calculator — Calculate your daily Dietary Reference Intakes (DRI) for vitamins, minerals, and macronutrients. Personalized RDA values based on age, sex, and activity.
IV Drops per Minute (Drip Rate) Calculator — Calculate IV drip rate in drops per minute from volume, time, and tubing drop factor. Includes mL/hr, seconds per drop, and maintenance rate references.
Due Date Calculator — Calculate your estimated due date (EDD) using Naegele's rule from your last menstrual period, conception date, or IVF transfer date. View trimester timeline and key milestones.
Estimated Due Date (EDD) Calculator — Calculate your estimated due date using LMP, ultrasound dating, or known conception date. Includes pregnancy timeline, gestational age, and term classifications.
Estimated Energy Requirement (EER) Calculator — Calculate your daily Estimated Energy Requirement using the IOM equation. Compare BMR methods, get AMDR macronutrient ranges, and plan for weight goals.
eGFR Calculator — Calculate estimated glomerular filtration rate using the CKD-EPI 2021 race-free equation. Determine chronic kidney disease stage and kidney function.
Egg Freezing Success Probability Calculator — Estimate egg freezing success rates by age. Calculate probability of live birth from frozen eggs based on oocyte survival, fertilization, and euploidy rates.
Effective Regurgitant Orifice Area (EROA) Calculator — Calculate EROA via PISA or volumetric method for mitral and aortic regurgitation severity grading. Includes regurgitant volume, fraction, and ASE severity tables.
Endotracheal Tube (ETT) Size Calculator — Calculate endotracheal tube size for pediatric and adult patients. Age-based formulas, size tables, insertion depth, suction catheter, and laryngoscope blade selection.
Exclusive Pumping Schedule & Volume Calculator — Calculate daily breast milk needs, pumping schedules, and supply tracking for exclusively pumping mothers. Includes storage guidelines and age-based schedules.
Face Shape Calculator — Determine your face shape from measurements. Get personalized eyewear, hairstyle, and makeup recommendations for oval, round, square, heart, diamond, oblong, and triangle face shapes.
Fagerström Test for Nicotine Dependence (FTND) Calculator — Assess nicotine dependence severity with the 6-item Fagerström Test. Get FTND score, dependence level, pharmacotherapy recommendations, and cessation treatment guidance.
Fractional Excretion of Sodium (FENa) Calculator — Calculate FENa to differentiate prerenal from intrinsic renal AKI. Includes FENa formula, AKI diagnostic indices comparison, and clinical interpretation with diuretic use guidance.
Fertility by Age Calculator — Estimate natural and IVF pregnancy rates by age. Includes cumulative probability, miscarriage and aneuploidy risk, AMH interpretation, and time-to-conceive milestones.
Fractional Excretion of Urea (FEUrea) Calculator — Calculate FEUrea to differentiate prerenal from intrinsic AKI in patients on diuretics. Includes FEUrea vs FENa comparison, AKI diagnostic indices, and clinical interpretation.
FIB-4 Index Calculator — Hepatic Fibrosis — Calculate the FIB-4 index for liver fibrosis staging using age, AST, ALT, and platelets. Includes age-adjusted cutoffs, APRI comparison, METAVIR staging, and referral guidance.
Fish Oil / Omega-3 Dosage Calculator — Calculate daily EPA and DHA omega-3 requirements by health condition. Includes dietary fish intake, supplement dosing, cost estimates, and fish omega-3 content reference table.
Finnegan Neonatal Abstinence Score (NAS) Calculator — Calculate the Finnegan NAS to assess neonatal opioid withdrawal severity. Includes 24-item scoring, treatment thresholds, pharmacologic management guidance, and category breakdowns.
Breast Pump Flange Size Calculator — Find your correct breast pump flange size based on nipple diameter and elasticity. Includes brand availability, fit assessment, size reference table, and signs of poor fit.
Free Testosterone Calculator (Vermeulen Method) — Calculate free and bioavailable testosterone using total testosterone, SHBG, and albumin. Includes age-adjusted references, SHBG interpretation, testosterone fractions visualization.
GAD-7 Anxiety Screening Calculator — Score the GAD-7 generalized anxiety disorder questionnaire. Includes severity interpretation, treatment recommendations, item-level analysis, symptom domains, and evidence-based treatment comparison.
Glasgow Coma Scale (GCS) Calculator — Calculate the Glasgow Coma Scale score from eye, verbal, and motor responses. Includes GCS-Pupils score, severity classification, airway decision support, mortality estimates, and motor score analy...
Glycemic Index & Glycemic Load Calculator — Calculate glycemic index and glycemic load for foods and meals. Includes 29-food reference database, meal GI calculator, GL classification, and blood sugar impact estimates.
Glucose Infusion Rate (GIR) Calculator — Calculate glucose infusion rate from dextrose concentration, IV rate, and weight. Includes neonatal/pediatric/adult targets, reverse calculation, dextrose concentration table, and hypoglycemia prot...
Glomerular Filtration Rate (GFR) Calculator — Calculate eGFR using CKD-EPI 2021, MDRD, Cockcroft-Gault, and Cystatin C equations. Includes CKD staging, KDIGO risk categories, drug dosing alerts, BUN:Cr ratio, and albuminuria classification.
Gorlin Formula Valve Area Calculator — Calculate cardiac valve area using the Gorlin formula from catheterization data including cardiac output, heart rate, and pressure gradient.
Gout Diagnosis Scoring Calculator — Score gout probability using the ACR/EULAR 2015 classification criteria with serum urate levels, joint involvement, and imaging findings.
GRACE ACS Risk Score Calculator — Calculate the GRACE score for acute coronary syndrome risk stratification including in-hospital and 6-month mortality prediction.
Growth Chart Percentile Calculator — Calculate height-for-age and weight-for-age percentiles for children 2-20 using CDC growth reference data. Track growth patterns and identify potential concerns.
Hand Sanitizer Effectiveness Calculator — Estimate hand sanitizer efficacy based on type, alcohol concentration, application time, volume, and hand condition with pathogen comparison.
Subjective Happiness Scale Calculator — Assess subjective happiness using the validated 4-item SHS by Lyubomirsky & Lepper with normative comparisons and well-being factor analysis.
hCG Levels and Doubling Time Tracker — Track hCG beta levels, calculate doubling time, and compare with expected ranges by gestational age for early pregnancy monitoring.
Hematocrit to Hemoglobin Ratio Converter — Convert between hematocrit and hemoglobin values with age/sex-adjusted normal ranges, anemia grading, and altitude correction.
Hearing Loss Frequency Calculator — Calculate Pure Tone Average (PTA) from audiogram frequencies and classify hearing loss severity using WHO criteria. Enter dB HL values for each frequency.
Heat Index Health Risk Calculator — Calculate the heat index (feels-like temperature) from air temperature and humidity. Get NWS health risk classification and outdoor activity safety guidelines.
HOMA-IR Insulin Resistance Calculator — Calculate HOMA-IR, HOMA-B beta cell function, and QUICKI index from fasting insulin and glucose to assess insulin resistance severity.
Hepatic Steatosis Index Calculator — Calculate the Hepatic Steatosis Index (HSI) to screen for non-alcoholic fatty liver disease using ALT, AST, BMI, diabetes status, and sex.
ICH Score Calculator — Calculate the Intracerebral Hemorrhage (ICH) score to predict 30-day and 12-month mortality from GCS, volume, IVH, location, and age.
ICH Volume Calculator (ABC/2 Method) — Estimate intracerebral hemorrhage volume using the ABC/2 method from CT imaging. Guides surgical decisions and prognosis in hemorrhagic stroke.
Incidence Rate Calculator — Calculate disease incidence rates per 1,000 or 100,000 person-time with confidence intervals. Compare periods and convert between epidemiologic measures.
Implantation Calculator — Estimate your implantation window and earliest pregnancy test date based on ovulation, LMP, or IVF transfer date. DPO 6-12 timeline with probability chart.
Isotretinoin (Accutane) Dose Calculator — Calculate isotretinoin cumulative dose, track treatment progress, and monitor lab values. Includes dosing by severity, iPLEDGE reminders, and lab schedules.
Injury Severity Score (ISS) Calculator — Calculate the Injury Severity Score from AIS ratings across 6 body regions. Includes NISS, RTS, TRISS survival probability, and mortality estimates.
IV Drip Rate Calculator — Calculate IV drip rate in drops per minute (gtts/min) and mL per hour from volume, time, and drop factor. Essential nursing and clinical reference tool.
Karvonen Formula Calculator — Calculate target heart rate zones using the Karvonen (Heart Rate Reserve) method. Compare 5 training zones with resting HR-adjusted targets for personalized exercise.
Kidney Failure Risk Equation (KFRE) Calculator — Estimate 2-year and 5-year risk of kidney failure using the KFRE model. Includes CKD staging, KDIGO heatmap, nephrology referral guidance, and dialysis planning.
Kidney Stone Calculator — Estimate spontaneous passage rates by stone size and location, treatment options, prevention strategies, and 24-hour urine interpretation for kidney stones.
Kt/V Calculator (Dialysis Adequacy) — Calculate Kt/V dialysis adequacy using the Daugirdas II formula. Includes spKt/V, eKt/V, URR, stdKt/V, Watson body water, and adequacy troubleshooting.
Local Anesthetic Dosing Calculator — Calculate maximum safe doses of local anesthetics (lidocaine, bupivacaine, ropivacaine) with and without epinephrine, plus LAST toxicity recognition.
Mask vs. No Mask Calculator — Compare respiratory infection transmission models with and without masking. Explore different mask types, compliance levels, and population-level impact.
MCA-PSV Doppler Calculator (Fetal Anemia) — Calculate MCA peak systolic velocity multiples of median (MoM) for fetal anemia detection using the Mari regression equation with interpretation guide.
Mcg to IU Converter (Vitamins) — Convert between micrograms (mcg) and International Units (IU) for Vitamin D, A, and E with RDA comparison and safety assessment.
Mean Airway Pressure & Oxygenation Index Calculator — Calculate mean airway pressure (MAP), oxygenation index (OI), P/F ratio, and driving pressure for conventional and HFOV ventilation with severity grading.
Mean Sac Diameter Calculator (Early Pregnancy) — Calculate mean gestational sac diameter, estimate gestational age, and assess early pregnancy viability using SOM 2012 and ACOG criteria.
Medical Radiation Dose Calculator — Calculate radiation dose from X-rays, CT scans, and nuclear medicine in mSv with background equivalents, cancer risk estimates, and fetal dose assessment.
Medical Unit Converter Calculator — Convert common lab values between conventional (US) and SI (international) units. Covers glucose, cholesterol, hemoglobin, creatinine, and 20+ lab tests.
Medication Dose by Weight Calculator — Calculate weight-based medication doses for common OTC medications. Get dose per kg calculations for acetaminophen, ibuprofen, and other non-prescription drugs.
Menstrual Cycle Tracker Calculator — Track your menstrual cycle phases — follicular, ovulatory, and luteal. Predict next period date, PMS window, and cycle regularity from your average cycle length.
Metastatic Prostate Cancer Prognosis Calculator — Estimate survival and risk stratification for metastatic prostate cancer using CHAARTED volume, Gleason score, PSA, and performance status.
MICA — Kidney Transplant Risk Calculator — Estimate kidney transplant graft survival using HLA mismatch, donor age, cold ischemia time, PRA, and sensitization status.
MIPI Score Calculator — Mantle Cell Lymphoma — Calculate the Mantle Cell Lymphoma International Prognostic Index (MIPI and MIPI-c) for risk stratification, survival estimation, and treatment guidance.
MME Calculator — Morphine Milligram Equivalents — Calculate total daily morphine milligram equivalents (MME) from multiple opioids with CDC risk thresholds, equianalgesic conversion, and naloxone guidance.
mmol/L to mg/dL Converter — Convert lab values between mmol/L and mg/dL for glucose, cholesterol, creatinine, calcium, and 14 common analytes with reference ranges and batch mode.
Mortality Rate Calculator — Calculate crude, cause-specific, case fatality, infant, neonatal, maternal mortality rates, PMR, and YPLL with interpretation and global benchmarks.
Navy PRT Calculator — Calculate Navy Physical Readiness Test scores for push-ups, plank, 1.5-mile run, and body composition assessment with age/sex-specific standards.
NEDOCS Calculator — Calculate the National Emergency Department Overcrowding Score to objectively assess ED crowding level and guide operational interventions.
NIH Stroke Scale (NIHSS) Calculator — Calculate the NIH Stroke Scale score to quantify stroke severity, guide treatment decisions, and predict outcomes with all 15 examination items.
Neutrophil-to-Lymphocyte Ratio (NLR) Calculator — Calculate NLR from CBC results with context-specific thresholds for sepsis, cardiac, oncology, COVID-19, and critical care. Includes PLR, LMR, and SII.
Number Needed to Treat (NNT) Calculator — Calculate NNT, NNH, ARR, RRR, relative risk, and odds ratio from clinical trial data with confidence intervals and cost-effectiveness analysis.
Noise Pollution & Hearing Risk Calculator — Calculate noise exposure dose, safe duration limits, and hearing damage risk with OSHA/NIOSH standards, dB combination, distance correction, and protection effectiveness.
Nuchal Translucency (NT) Screening Calculator — Calculate first-trimester screening risk for Trisomy 21, 18, and 13 using NT measurement, maternal age, nasal bone, and biochemistry markers.
Opioid Withdrawal (COWS) Calculator — Score opioid withdrawal severity using the Clinical Opiate Withdrawal Scale (COWS) with buprenorphine induction guidance and treatment recommendations.
Osmolality Gap Calculator — Calculate serum osmolality and osmolal gap. Detect toxic alcohol ingestion (methanol, ethylene glycol) with clinical interpretation.
Ovulation Calculator — Calculate your ovulation day and fertile window based on your last menstrual period and cycle length. Identify up to 6 fertile days each month for conception planning.
Pack-Years Calculator — Calculate pack-year smoking history for lung cancer screening eligibility, COPD risk assessment, and cardiovascular risk evaluation.
Parkland Formula (Burn Resuscitation) Calculator — Calculate IV fluid resuscitation for burn patients using the Parkland formula with Rule of Nines TBSA estimation, delayed presentation adjustment, and pediatric dosing.
PECARN Pediatric Head Injury Calculator — Apply the PECARN head injury decision rule for children with minor head trauma to determine CT necessity, risk-stratify ciTBI, and guide observation vs imaging decisions.
Pediatric BMI Percentile Calculator — Calculate BMI-for-age percentile for children ages 2-20. Classify weight status using CDC growth chart categories: underweight, normal, overweight, and obese.
Period & Menstrual Cycle Calculator — Track your menstrual cycle, predict next period and ovulation dates, identify fertile windows, and understand cycle phases with this free period calculator.
PISA Calculator — Proximal Isovelocity Surface Area — Calculate EROA and regurgitant volume using the PISA method for valvular regurgitation assessment. Grade mitral, aortic, and tricuspid regurgitation severity.
Plasma Volume Calculator — Estimate total blood volume, plasma volume, and red cell volume using Nadler, Lemmens, or Gilcher methods. Calculate allowable blood loss for surgical planning.
Pregnancy Weight Gain Calculator — Calculate recommended pregnancy weight gain based on IOM 2009 guidelines and pre-pregnancy BMI. Track trimester-specific weight gain targets for singles and twins.
Prescription Refill Date Calculator — Calculate when to refill your prescription based on pill count, dosing frequency, and lead time. Plan ahead to never run out of medication.
Post-Void Residual Volume (PVR) Calculator — Calculate and interpret post-void residual urine volume, voiding efficiency, and flow rate. Assess urinary retention severity and guide clinical evaluation.
Pneumonia Severity Index (PSI/PORT) Calculator — Calculate the PSI/PORT score to assess pneumonia severity, predict 30-day mortality, and guide inpatient vs. outpatient treatment decisions.
Qp/Qs Ratio Calculator — Pulmonary-to-Systemic Flow — Calculate the Qp/Qs ratio from cardiac catheterization oxygen saturations to quantify intracardiac shunts. Assess ASD, VSD, and PDA hemodynamic significance.
QTc Calculator — Corrected QT Interval — Calculate corrected QT interval using Bazett, Fridericia, Framingham, and Hodges formulas. Assess risk for QT prolongation and Torsades de Pointes.
Quarantine Activity & Indoor Exercise Planner — Plan effective indoor workouts during quarantine or home isolation. Calculate calories burned for bodyweight exercises, yoga, HIIT, and more based on your space and fitness level.
QUICKI Insulin Sensitivity Calculator — Calculate the Quantitative Insulin Sensitivity Check Index (QUICKI), HOMA-IR, and HOMA-β from fasting insulin and glucose to assess insulin resistance and beta-cell function.
Rate Pressure Product (RPP) Calculator — Calculate Rate Pressure Product to estimate myocardial oxygen demand. Includes triple product, MAP, angina threshold assessment, and hemodynamic reference ranges.
RCRI — Revised Cardiac Risk Index Calculator — Calculate RCRI (Lee Index) for perioperative cardiac risk stratification. Estimates major adverse cardiac event probability before non-cardiac surgery using 6 clinical predictors.
REM Sleep & Sleep Cycle Calculator — Estimate your REM sleep, deep sleep, and sleep cycle distribution based on total sleep time, age, and sleep quality factors. Includes cycle-by-cycle breakdown and optimization tips.
Type 2 Diabetes Risk Calculator (FINDRISC) — Assess your 10-year type 2 diabetes risk using the Finnish Diabetes Risk Score (FINDRISC). Includes ethnicity adjustment, modifiable risk factor analysis, and ADA screening criteria.
RSBI — Rapid Shallow Breathing Index Calculator — Calculate the Rapid Shallow Breathing Index (f/VT) for ventilator weaning assessment. Includes weaning readiness checklist, P/F ratio, and predictive performance data.
RMR — Resting Metabolic Rate Calculator — Calculate your resting metabolic rate using Mifflin-St Jeor, Harris-Benedict, Katch-McArdle, and Cunningham formulas. Get TDEE, calorie targets, and macronutrient estimates.
SAPS II — Simplified Acute Physiology Score Calculator — Calculate the SAPS II ICU severity score from 17 variables. Estimates hospital mortality risk for critically ill patients using the worst values in the first 24 hours of ICU admission.
SAAG — Serum-Ascites Albumin Gradient Calculator — Calculate the Serum-Ascites Albumin Gradient to differentiate portal hypertensive from non-portal ascites. Includes SBP screening, LDH analysis, and diagnostic algorithm.
Sleep Time Calculator — Bedtime & Wake Cycle Planner — Calculate the ideal bedtime based on your wake-up time, sleep cycles, and age. Aligns with 90-minute cycles and National Sleep Foundation recommendations.
SCORAD — Atopic Dermatitis Severity Calculator — Calculate the Scoring Atopic Dermatitis (SCORAD) index to assess eczema severity. Evaluates extent, intensity, and subjective symptoms with treatment step recommendations.
Sobriety & BAC Calculator — Blood Alcohol Estimator — Estimate your current blood alcohol concentration (BAC), time to sober, and impairment level using the Widmark formula. Includes hourly BAC timeline and effects reference.
Social Distancing & Exposure Risk Calculator — Estimate respiratory illness transmission risk based on distance, duration, masks, ventilation, vaccination status, and community prevalence. Includes mitigation checklist.
Semen Analysis Calculator — WHO 2021 Reference Values — Interpret semen analysis results against WHO 2021 (6th edition) reference limits. Calculates total motile count, functional sperm, and ART suitability assessment.
Standard Drink Calculator — Alcohol Content Converter — Convert any alcoholic beverage to standard drinks (US, UK, AU, CA). Calculate pure alcohol grams, calories, metabolism time, and compare 15+ common drink types.
Corticosteroid Conversion Calculator — Steroid Equivalency — Convert between corticosteroids using equipotent dose equivalency. Compares 8 steroids with relative potency, mineralocorticoid activity, half-life, and HPA suppression risk.
STOP-BANG Score — OSA Screening Calculator — Screen for obstructive sleep apnea risk using the STOP-BANG questionnaire. 8 yes/no questions with risk stratification, perioperative guidance, and predictive performance data.
Swiss Cheese Model — Layered Protection Calculator — Visualize and calculate the cumulative risk reduction from multiple preventive layers (masks, distance, ventilation, vaccines, testing) using the Swiss Cheese model of pandemic defense.
Testosterone to Estradiol Ratio (T:E2) Calculator — Calculate the testosterone-to-estradiol ratio for hormonal balance assessment. Supports ng/dL & nmol/L units, male reference ranges, clinical interpretation, and estradiol status evaluation.
Time of Death Estimator — Postmortem Interval (PMI) Calculator — Estimate time since death using Henssge nomogram body cooling model. Factors in body temperature, ambient temperature, weight, clothing, body build, and environment with postmortem changes timeline.
Tinetti Assessment Tool — Balance & Gait Fall Risk Calculator — Score the Tinetti Performance-Oriented Mobility Assessment (POMA) with 10 balance and 10 gait items. Calculates total score, fall risk category, component subscores, and visual progress bars.
ACR TI-RADS Calculator — Thyroid Nodule Risk Stratification — Score thyroid nodules using ACR TI-RADS (Thyroid Imaging Reporting and Data System). Evaluates 5 ultrasound features, calculates points, assigns TI-RADS level, and provides FNA recommendations.
tPA (Alteplase) Dosing Calculator — Stroke & PE — Calculate tPA (alteplase) dosing for acute ischemic stroke (0.9 mg/kg) and massive PE (100 mg). Includes bolus/infusion split, contraindication screening, time window check, and ICH risk estimate.
TTKG Calculator — Transtubular Potassium Gradient — Calculate the transtubular potassium gradient (TTKG) to assess renal potassium handling in hyperkalemia and hypokalemia. Includes interpretation, validity checks, and differential diagnosis tables.
Twinning Rate Calculator — Twin Pregnancy Probability — Estimate your probability of a twin pregnancy based on maternal age, ethnicity, family history, parity, BMI, prior twins, and IVF/embryo transfer count. Includes DZ/MZ breakdown and ethnic comparison.
Urine Output Calculator — mL/kg/hr & AKI Staging — Calculate urine output rate (mL/kg/hr), classify oliguria/anuria/polyuria, and assess KDIGO AKI staging by urine output. Supports adults, children, infants, and neonates with hourly tracking.
UV Exposure Time Calculator — Calculate safe sun exposure time based on UV index, skin type (Fitzpatrick I–VI), and SPF. Get sunscreen reapplication schedules and UV protection guidelines.
URR & Kt/V Calculator — Dialysis Adequacy — Calculate urea reduction ratio (URR) and Kt/V (Daugirdas) for hemodialysis adequacy assessment. Includes eKt/V, UF rate monitoring, KDOQI targets, and troubleshooting for low clearance.
SIR Model Epidemic Simulator — Viral Infection Spread — Simulate viral epidemic spread using the SIR (Susceptible-Infected-Recovered) compartmental model. Set R₀, vaccination, interventions, and view epidemic curves, peak timing, attack rates, and herd...
Vision Prescription Converter Calculator — Convert between vision prescription formats including diopters, Snellen, and LogMAR. Plus glasses-to-contacts conversion with vertex distance correction.
Wake-Up Time & Sleep Cycle Calculator — Find ideal bedtimes or wake-up times aligned to 90-minute sleep cycles. Includes sleep stage visualization, NSF age-specific recommendations, and sleep hygiene tips.
Vital Capacity & Spirometry Calculator — FVC, FEV₁, GOLD Staging — Calculate predicted FVC, FEV₁, and PEF based on age, sex, height, and ethnicity. Compare measured values to identify obstructive, restrictive, or normal patterns. Includes GOLD COPD staging.
Free Water Deficit Calculator — Hypernatremia Correction — Calculate free water deficit for hypernatremia correction with TBW-based formula and Adrogue-Madias. Includes safe correction rates, IV fluid selection, correction timeline, and hypernatremia diffe...
Warsaw Method — Neonatal Fluid Calculator — Calculate neonatal fluid requirements using the Warsaw graduated fluid protocol. Supports ELBW, VLBW, and term neonates with IWL adjustments for phototherapy, radiant warmers, and humidified incuba...
Winters' Formula Calculator — ABG Acid-Base Analysis — Calculate expected pCO₂ for metabolic acidosis using Winters' formula. Full ABG acid-base analysis with anion gap (albumin-corrected), delta-delta ratio, compensation assessment, and MUDPILES diff...
Wind Chill Health Risk Calculator — Calculate wind chill temperature from air temperature and wind speed. Get NWS frostbite risk times and cold weather safety guidelines for outdoor activity.