BMR calculator
BMR calculator: calories you burn at rest.
EstimateBMR (Mifflin-St Jeor)
Estimate. BMR is what you burn at complete rest; your daily needs are higher once you add movement.
It estimates your basal metabolic rate, the calories your body burns at complete rest, with the Mifflin-St Jeor equation. Add your body fat percentage to compare it with Katch-McArdle.
Track this target in Calowly.
Set your calorie target in the app and snap your meals. Calo shows how each one fits your day, so the number on this page turns into what you actually eat.
How it works
BMR is the energy your body needs at complete rest. The main result uses the Mifflin-St Jeor equation, which works from your weight, height, age and sex. If you enter your body fat percentage, the calculator also shows Katch-McArdle, which works from lean body mass instead:
Men: BMR = 10 × weight in kg + 6.25 × height in cm − 5 × age + 5
Women: BMR = 10 × weight in kg + 6.25 × height in cm − 5 × age − 161
Katch-McArdle: BMR = 370 + 21.6 × lean body mass in kg
Your BMR does not include walking, exercise or digesting food, so your daily needs are higher. To get those, the TDEE calculator multiplies your BMR by an activity factor.
Example: a 30-year-old man who weighs 80 kg and is 180 cm tall has a BMR of 10 × 80 + 6.25 × 180 − 5 × 30 + 5 = 1,780 kcal. At 20% body fat his lean mass is 64 kg, so Katch-McArdle gives 370 + 21.6 × 64 ≈ 1,752 kcal.
Common questions
What is BMR?
Basal metabolic rate is the energy your body uses at complete rest to keep you alive: breathing, circulation, keeping warm and repairing cells. It is usually the largest part of your daily calorie burn, but it does not include walking, exercise or digestion. Those are added in your TDEE.
Which BMR formula is most accurate?
For most healthy adults, Mifflin-St Jeor is the equation most often recommended, and it is the main result here. If you know your body fat percentage, Katch-McArdle can be closer for very lean or very muscular people, because it works from lean mass instead of total body weight.
How do I measure my body fat percentage?
Common options are smart scales, skinfold calipers and DEXA scans. Home scales are convenient but can be off by several percentage points, so treat the Katch-McArdle result as a rough check. If you do not know your body fat, leave the field empty and use the Mifflin-St Jeor result.
Should I eat less than my BMR to lose weight?
No. Your BMR is what your body needs at rest, and your daily needs are higher once you add movement. A weight-loss target is set below your TDEE, not below your BMR. The calorie deficit calculator does exactly that and never goes below 1,200 kcal for women or 1,500 for men.
Can I raise my BMR?
Building muscle raises it a little, because lean tissue uses more energy than fat, while it tends to drift down slowly with age and weight loss. The bigger lever for your daily calorie burn is movement, from walking to training, and that is counted in your TDEE rather than your BMR.
Related calculators
Calorie database: Calories and macros per 100g and per serving for everyday foods.
Sources
Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr 1990;51(2):241-7. doi:10.1093/ajcn/51.2.241
McArdle WD, Katch FI, Katch VL. Exercise Physiology (Katch-McArdle equation).
Formula and text last reviewed on 24 September 2026.
This calculator gives general estimates for healthy adults and is not medical advice. If you are pregnant, breastfeeding, or have a medical condition or an eating disorder, talk to a doctor or dietitian before changing how you eat.