Running pace, heart rate zones, VO2max, cycling FTP, and calorie burn calculators. Browse our free cardio & endurance tools below — all calculators are instant, accurate, and require no sign-up.
5K/10K Training Pace Calculator — Calculate training paces for 5K and 10K races using VDOT-based methodology. Get easy, tempo, interval, and repetition pace zones from a recent race time.
Average Triathlon Finish Times Calculator — Estimate triathlon finish times based on your swim, bike, and run pace. Compare with average finish times across Sprint, Olympic, 70.3, and Ironman distances.
Bike Cadence Calculator — Calculate your optimal cycling cadence (RPM) based on speed, gear ratio, and wheel size. Find the right pedaling rhythm for efficient riding.
Bike Cadence and Speed Calculator — Convert between cycling cadence (RPM), speed, and gear ratio. Find the perfect balance of pedaling rate and velocity for any terrain.
Bike Gear Calculator — Calculate gear ratios, gear inches, development, and speed for any bicycle drivetrain. Compare gears across cassettes and chainrings.
Bike Pace Calculator — Calculate cycling pace, speed, time, and distance for any ride. Convert between km/h, mph, min/km, and min/mi for training planning.
Bike Size Calculator — Find your ideal bike frame size based on height, inseam, and riding style. Get recommendations for road, mountain, and hybrid bikes.
Bike Speed Calculator — Calculate cycling speed from distance and time, or estimate speed based on power, weight, terrain, and wind. Convert between mph and km/h.
Calories Burned by Activity Calculator — Calculate calories burned for 100+ activities using MET values from the Compendium of Physical Activities. Enter your weight, activity, and duration.
Calories Burned by Heart Rate Calculator — Estimate calories burned from heart rate data. Uses validated formulas for men and women based on HR, age, weight, and duration.
Chain Length Calculator — Calculate the correct bicycle chain length for any drivetrain. Determine links needed based on chainring, cassette, and chainstay length.
Cycling Breakaway Calculator — Calculate time gaps, catch rates, and breakaway success probability for cycling races. Analyze peloton vs breakaway dynamics.
Cycling Calorie Calculator — Calculate calories burned cycling from power data or MET-based estimates. Supports indoor trainer and outdoor riding with adjustable intensity.
Cycling FTP Calculator — Calculate your Functional Threshold Power (FTP) from a 20-minute test, ramp test, or 8-minute test. Set Coggan power zones for structured cycling training.
Cycling Heart Rate Calculator — Calculate cycling heart rate zones, training intensities, and target HR ranges. Personalized zones based on max HR or lactate threshold.
Cycling Wattage Calculator — Calculate cycling power output (watts) from speed, weight, gradient, and wind. Estimate FTP and watts per kilogram for performance tracking.
Cycling Zones Calculator — Calculate personalized cycling power and heart rate training zones. Set zones from FTP or max HR for structured training programs.
E-Bike Range Calculator — Estimate electric bike range based on battery capacity, motor power, terrain, rider weight, and assist level. Plan rides with confidence.
EPOC Estimator Calculator — Estimate your Excess Post-Exercise Oxygen Consumption (EPOC) or afterburn effect based on workout intensity, duration, and fitness level.
Earned Run Average (ERA) Calculator — Calculate a pitcher's ERA from innings pitched and earned runs. Includes WHIP, K/9, FIP, and complete pitching statistics analysis.
Fat Burning Zone Calculator — Calculate your optimal fat burning heart rate zone based on age, resting HR, and fitness level. Maximize fat oxidation during exercise.
Half Marathon Pace Calculator — Calculate your ideal half marathon pace per mile and per km from a target finish time. Includes mile-by-mile splits, negative-split strategy, and nutrition timing.
Heart Rate Recovery Calculator — Measure and evaluate your heart rate recovery (HRR) after exercise. Assess cardiovascular fitness and track recovery improvement over time.
Heart Rate Zone Calculator (Karvonen Method) — Calculate your 5 heart rate training zones using the Karvonen formula. Enter your age and resting heart rate for personalized zone targets.
HIIT Calorie Burn Calculator — Calculate calories burned during HIIT (High-Intensity Interval Training) workouts. Factor in work/rest intervals, rounds, and EPOC afterburn effect.
Running Cost Calculator (Cost Per Mile/Km) — Calculate the true cost per mile or kilometer of running. Factor in shoes, gear, race fees, nutrition, and maintenance for complete running expense analysis.
Marathon Pace Calculator — Calculate your ideal marathon pace per mile and per kilometer from a target finish time, with mile-by-mile split tables and negative-split strategies.
Max Heart Rate Calculator — Estimate your maximum heart rate using 7 research-backed formulas: Fox (220-age), Tanaka, Gulati (women), Gellish, Nes, Fairbarn, and Oakland.
MET Value Calculator — Calculate Metabolic Equivalent of Task (MET) values and convert them to calories burned. Compare MET values across activities and intensity levels.
Miles to Steps Converter Calculator — Convert miles or kilometers to steps and vice versa. Estimate step count based on distance, height, and walking or running stride length.
Pace Zone Calculator — Calculate training pace zones from your threshold pace or a recent race result. Get Jack Daniels or Pfitzinger style zones for structured running training.
Race Time Predictor Calculator — Predict your finish times for 5K, 10K, half marathon, marathon, and custom distances using the Riegel and Cameron formulas from a known race result.
Rowing Pace Calculator — Calculate rowing split time, watts, and calories from ergometer data. Convert between pace per 500m, watts, and calorie rate for erg training.
Running Calorie Calculator — Calculate calories burned running based on pace, distance, weight, and terrain. Includes MET values, net vs gross calories, and pacing strategies.
Running Pace Calculator — Convert between running pace (min/mi, min/km) and speed (mph, km/h). Calculate finish times for any distance from your pace or speed.
Running Split Calculator — Plan your race splits mile-by-mile or km-by-km. Choose even, negative, or positive split strategies for 5K, 10K, half marathon, or marathon.
Running Splits Calculator — Generate even, negative, or positive split tables for any race distance. Plan mile and kilometer splits with pacing strategies for 5K to marathon.
Step Calorie Calculator — Calculate how many calories you burn from walking or running steps. Estimate calorie expenditure based on step count, body weight, pace, and stride length.
Swimming Calorie Calculator — Calculate calories burned swimming by stroke, intensity, and duration. Compare energy burn across strokes with MET-based estimates and distance tracking.
Swimming Time Calculator — Calculate swimming time for any distance based on pace. Estimate split times, convert between swimming units, and compare paces across strokes and distances.
Tabata Interval Calculator — Calculate the calorie burn and training load of Tabata-style workouts. Classic 20s work / 10s rest protocol with customizable exercises and rounds.
Target Heart Rate Calculator — Calculate your target heart rate range for any exercise intensity. Uses both %HRmax and Karvonen methods. Perfect for beginners and fitness enthusiasts.
Training Load (TRIMP) Calculator — Calculate your TRIMP training load using Banister's model. Track session intensity with heart rate data and monitor acute vs chronic training load ratio.
Triathlon Calculator — Plan your triathlon race with split time predictions, pacing strategy, nutrition planning, and transition optimization across Sprint, Olympic, 70.3, and Ironman distances.
Triathlon Training Plan Calculator — Generate a personalized triathlon training plan with weekly volume, discipline breakdown, and periodization. Build plans for Sprint through Ironman with progressive overload.
VO2 Max Calculator — Estimate your VO2 max from common field tests: Cooper Test, 1.5 Mile Run, Rockport Walk Test, and step tests. Assess aerobic fitness level.
VO2 Max Calculator for Runners — Estimate VO2 max from your race results. Use 5K, 10K, half marathon, or marathon times to calculate aerobic capacity and predict race performances.
VO2max Calculator (Cooper 12-Minute Run Test) — Estimate your VO2max from the Cooper 12-minute run test. Enter the distance you covered to get your aerobic fitness rating and age-based percentile.
VO2max Calculator (Rockport Walk Test) — Estimate your VO2max with the Rockport 1-mile walk test. Accessible for all fitness levels. Enter your walk time, heart rate, weight, age, and sex.
Walking Calorie Calculator — Calculate calories burned walking based on pace, distance, weight, and incline. Includes step count estimates and walking vs running comparisons.
Watts per Kilogram Calculator — Calculate your cycling power-to-weight ratio (W/kg) from FTP and body weight. Compare to amateur and pro benchmarks by category.