BMR & TDEE Calculator
Find your basal metabolic rate (BMR) and total daily energy expenditure (TDEE) from your age, sex, height, weight, and activity level, the calorie baseline for any diet. Runs in your browser.
Maintenance calories (TDEE)
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Show the math
BMR uses the Mifflin-St Jeor equation, then TDEE scales it by activity:
BMR = 10·kg + 6.25·cm − 5·age + (men +5 / women −161)
TDEE multiplies BMR by an activity factor from 1.2 (sedentary) to 1.9 (very active). These factors are a widely used convention rather than a measured standard; the FAO/WHO/UNU expert report puts most adults' activity levels between 1.4 and 2.4 times BMR, so check your result against how your weight actually changes. The goal lines subtract a deficit (about 7,700 kcal per kilogram, spread over a week) so −0.5 kg/week is roughly 550 fewer calories a day. Mifflin-St Jeor was developed on adults aged 19 to 78, and loss targets below about 1,200 kcal a day for women or 1,500 for men are flagged: diets that low should be medically supervised.
What this does
A BMR & TDEE calculator finds your basal metabolic rate (the energy you burn at rest) and total daily energy expenditure (rest plus activity) from your age, sex, height, weight, and activity level.
How it works
It estimates BMR with the Mifflin-St Jeor equation, then multiplies by an activity factor (1.2 to 1.9) to get TDEE, roughly the calories you burn in a typical day. The activity factors are a widely used convention, not a measured standard, so check the result against how your weight actually changes.
BMR = 10 × kg + 6.25 × cm − 5 × age + 5 (men) or − 161 (women); TDEE = BMR × activity factor
How to use it
- Enter your age, sex, height, and weight.
- Choose your activity level honestly.
- Read your BMR and TDEE.
- Use TDEE as your maintenance-calorie baseline.
Understanding your result
To lose weight, eat below TDEE; to gain, eat above it. Most people overestimate activity, so lean conservative and adjust based on real results over a few weeks.
Example
A 30-year-old woman, 165 cm and 65 kg, has a BMR of about 1,370 kcal (Mifflin-St Jeor) and a TDEE of about 2,124 kcal at moderate activity (× 1.55).
Sources & methodology
- USDA, Dietary Guidelines for Americans, Calorie needs and healthy eating
- NIH, Body Weight Planner, Energy balance and weight change
- Harvard Health Publishing, Calorie counting made easy, Minimum intake without medical supervision: 1,200 kcal (women), 1,500 kcal (men)
- NIDDK, Very low-calorie diet (definition), About 800 kcal a day or less, under medical supervision
Last updated .
Frequently asked questions
Why are some weight-loss lines flagged?
A standard 0.25 or 0.5 kg a week deficit can push a small or less active person below about 1,200 kcal a day (1,500 for men), lower than generally advised without medical supervision. Those lines are marked, and anything under 800 kcal is shown as "Under 800 kcal" rather than a number. The equation was developed on adults aged 19 to 78.
What is the difference between BMR and TDEE?
BMR is the energy your body burns at complete rest just to stay alive. TDEE multiplies BMR by an activity factor to include movement and exercise, it is roughly the calories you burn in a typical day.
Which formula do you use?
The Mifflin-St Jeor equation, widely regarded as the most accurate general BMR formula. It uses your weight, height, age, and sex.
How do I pick an activity level?
Be honest and lean conservative, most people overestimate. Sedentary is desk work with little exercise; moderate is training 3–5 days a week. The factors are a common convention rather than a measured standard, so adjust based on real results.
Is my data stored?
No. Everything is calculated locally in your browser.
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