Enter your age, sex, height, weight, and activity level to get your Total Daily Energy Expenditure — the calories you burn per day — plus your BMR and calorie targets for cutting or bulking.
How the TDEE calculator works
Your body burns calories two ways: keeping you alive (your Basal Metabolic Rate, or BMR — breathing, circulation, cell repair) and everything else (moving, digesting, training). This calculator first estimates your BMR with the Mifflin-St Jeor equation, then multiplies it by an activity factor to get your Total Daily Energy Expenditure — the calories you actually burn in a typical day. Eat that many calories and your weight holds steady; eat above or below it and it moves.
The formula
Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
TDEE = BMR × activity factor (1.2 – 1.9)
Weight is in kilograms and height in centimeters (US units are converted for you). The activity factor ranges from 1.2 for sedentary up to 1.9 for hard daily training.
Worked example
A 30-year-old man, 178 cm (about 5′10″), 75 kg (about 165 lbs), training 3–5 days a week (moderate, ×1.55):
BMR = 10 × 75 + 6.25 × 178 − 5 × 30 + 5 = 750 + 1,112.5 − 150 + 5 = 1,718 kcal
TDEE = 1,717.5 × 1.55 ≈ 2,662 kcal/day
To cut, he'd eat around 2,162 kcal (−500); to lean bulk, around 2,912 kcal (+250).
Why Mifflin-St Jeor, and why every number here is an estimate
For most of the 20th century, calculators used the Harris-Benedict equation, published in 1919. It was built on a small sample of early-1900s adults and tends to overestimate modern BMRs by about 5%. The Mifflin-St Jeor equation (1990) was derived from a larger, more representative sample and validates better against measured metabolic rates, which is why the American Academy of Nutrition and Dietetics recommends it. Even so, any equation only predicts within about ±10% for most people — muscle mass, genetics, and hormones all move the real number. Use your result as a starting line, not a verdict: eat at your calculated TDEE for two or three weeks, watch the scale, and adjust by 100–200 calories at a time.
Frequently asked questions
What is the difference between BMR and TDEE?
BMR (Basal Metabolic Rate) is what your body burns at complete rest — just keeping your organs running. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor to account for everything else you do: walking, working, training. TDEE is the number to use for setting calorie targets.
How many calories should I eat to lose weight?
A common starting point is 250–500 calories below your TDEE, which works out to roughly 0.5–1 lb of fat loss per week. Steeper deficits work faster but are harder to sustain and cost more muscle. This calculator shows both a mild cut (−250) and a standard cut (−500) for your numbers.
Which activity level should I pick?
Most people overestimate. If you have a desk job and train 3–5 times a week, "moderate" (1.55) is usually right. Only pick "very" or "extra" active if you train hard nearly every day or do physical labor. When in doubt, pick the lower level, track your weight for two weeks, and adjust.
Is the Mifflin-St Jeor equation accurate?
It is the most accurate general-population BMR equation available without lab testing — studies find it predicts measured BMR within 10% for most adults. But it is still an estimate: genetics, muscle mass, and hormones all shift your true burn, so treat the result as a starting point and adjust based on real-world results.
Why does my TDEE seem lower than what my fitness tracker says?
Wrist trackers routinely overestimate calorie burn from exercise, sometimes by 20–40%. The Mifflin-St Jeor estimate is deliberately conservative. If the two disagree, trust the scale over either: eat at your calculated TDEE for two to three weeks, and whichever direction your weight moves tells you the true number.