Calculate how many calories you need per day based on age, sex, weight, height, and activity level. Get your TDEE with goal-based adjustments.
Your daily calorie needs — also called Total Daily Energy Expenditure (TDEE) — represent the total number of calories your body burns each day through basal metabolism, physical activity, and the thermic effect of food. Knowing this number is the foundation for any nutrition plan, whether your goal is weight loss, muscle gain, or simply maintaining your current weight.
This calculator estimates your TDEE using one of four established BMR formulas (Mifflin-St Jeor, Harris-Benedict, Katch-McArdle, or Cunningham) multiplied by an activity factor that reflects your daily movement patterns. You can then adjust the result based on your goal: create a calorie deficit for fat loss, eat at maintenance for weight stability, or add a surplus for muscle building.
The Mifflin-St Jeor equation is the default because research published in the Journal of the American Dietetic Association found it to be the most accurate BMR predictor for both normal-weight and obese individuals. However, if you know your body fat percentage, the Katch-McArdle formula may provide a more personalized estimate by accounting for lean body mass.
Guessing your calorie needs leads to either under-eating (low energy, muscle loss, metabolic slowdown) or over-eating (unwanted fat gain). A calculated TDEE gives you a science-based starting point that you can refine over time. By knowing your maintenance calories, you can create precise deficits for fat loss (250–500 kcal below TDEE) or surpluses for muscle gain (250–500 kcal above TDEE), making your nutrition plan intentional rather than random.
TDEE = BMR × Activity Factor BMR Formulas: • Mifflin-St Jeor: 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161 (F) or + 5 (M) • Harris-Benedict (revised): 447.593 + 9.247 × weight(kg) + 3.098 × height(cm) − 4.330 × age (F); 88.362 + 13.397 × weight(kg) + 4.799 × height(cm) − 5.677 × age (M) • Katch-McArdle: 370 + 21.6 × lean mass(kg) • Cunningham: 500 + 22 × lean mass(kg) Activity Factors: Sedentary: 1.2 | Light: 1.375 | Moderate: 1.55 | Active: 1.725 | Extra Active: 1.9
Result: 2,726 calories/day
Using Mifflin-St Jeor for a 30-year-old male, 178 cm, 80 kg: BMR = 10(80) + 6.25(178) − 5(30) + 5 = 800 + 1112.5 − 150 + 5 = 1,767.5 kcal. With a moderate activity factor of 1.55: TDEE = 1,767.5 × 1.55 = 2,740 kcal/day. This is the estimated number of calories needed to maintain current weight.
Your body expends energy in three main ways: Basal Metabolic Rate (BMR) accounts for 60–75% of total expenditure and covers basic life-sustaining functions like breathing, circulation, and cell repair. Physical activity accounts for 15–30%, and the thermic effect of food (TEF) — the energy cost of digestion — accounts for about 10%. TDEE is the sum of all three.
The Mifflin-St Jeor equation (1990) was validated as the most accurate population-level BMR estimator in a 2005 review published in the Journal of the American Dietetic Association. For individuals with known body composition, the Katch-McArdle formula provides a lean-mass-based estimate that better handles variations in muscle-to-fat ratio. Athletes and very muscular individuals often find Katch-McArdle more accurate.
No calculator is perfectly accurate for every individual — TDEE formulas have a ±10–15% margin of error. Use the result as a starting point, eat that amount consistently for 2–4 weeks, monitor your weight trend, and adjust. If your weight is stable, you've found your true maintenance. If it's trending up or down by 0.5–1 lb/week, adjust intake by ±250 calories and reassess.
For fat loss, a moderate deficit of 300–500 calories below TDEE is sustainable for most people. For muscle gain, a surplus of 200–400 calories above TDEE supports growth while minimizing fat gain. Extreme deficits (>750 kcal) or surpluses (>500 kcal) are generally counterproductive for long-term body composition goals.
It depends on your age, sex, size, and activity level. Most adult men need 2,200–3,000 calories/day and most adult women need 1,800–2,400 calories/day for maintenance. This calculator provides a personalized estimate based on your specific inputs. Adjust based on whether your goal is weight loss, gain, or maintenance.
The Mifflin-St Jeor equation is considered the most accurate for the general population by the American Dietetic Association. If you know your body fat percentage, the Katch-McArdle formula may be more accurate because it uses lean body mass, which better accounts for individual body composition differences.
Sedentary: desk job, minimal exercise. Light: 1–3 days/week of light exercise. Moderate: 3–5 days/week of moderate exercise. Active: 6–7 days/week of hard exercise or physical job. Extra active: intense daily training or very physically demanding job. When in doubt, choose one level lower than you think.
The TDEE method already accounts for exercise in the activity multiplier, so you don't need to add exercise calories on top. If you track exercise calories separately (like with a fitness tracker), be cautious — devices often overestimate calorie burn by 15–30%. Eating back half of tracked exercise calories is a safer approach.
Fitness trackers use heart rate and motion data to estimate calorie burn, while TDEE formulas use statistical equations. Both are estimates with margins of error (typically ±10–15%). If they disagree significantly, use the average of both and adjust based on real-world weight trends over 2–4 weeks.
A deficit of 500 calories/day below TDEE produces approximately 1 lb/week of weight loss (though the actual rate varies). Most health organizations recommend 0.5–2 lbs/week for sustainable fat loss. Faster rates increase muscle loss risk, metabolic adaptation, and are harder to maintain long-term.
The TDEE method averages your activity over the week, so the same daily intake works for most people. However, some prefer calorie cycling — eating more on training days and less on rest days while keeping the weekly total the same. Both approaches can be effective.
Yes, but less dramatically than commonly believed. BMR decreases about 1–2% per decade after age 20, primarily due to loss of lean muscle mass. Maintaining muscle through resistance training can significantly offset this decline. The age factor in BMR formulas accounts for this average decrease.