BMR Calculator

Written byOleh Soloninupdated 27 September 2026

Sex

Age

Weight kg

Height cm

Result

BMR1,696

This result is informational only and is not professional advice.

What your body spends doing nothing at all

Calculate basal metabolic rate with the Mifflin-St Jeor equation. This is the floor of your daily energy use, before any activity.

Basal metabolic rate is what keeps you alive lying still: heart, lungs, brain, temperature. For a sedentary person it is 83 percent of the day's expenditure; for a moderately active one, 65 percent.

It is not your daily target. BMR is the baseline you multiply by an activity factor to get total expenditure — eating only at BMR level would be a substantial deficit for anyone who moves.

How to use

Choose your sex.
Enter your age in years, weight in kilograms and height in centimetres.
The result is your BMR in kilocalories a day by the Mifflin-St Jeor equation.
For daily needs, multiply it by an activity factor — or open the calorie calculator, which does that for you.

How BMR is calculated

Mifflin-St Jeor: 10 × weight in kg + 6.25 × height in cm − 5 × age, plus 5 for men and minus 161 for women. Each kilogram adds 10 kcal and each year takes off 5, so a decade costs 50 kcal in the equation.

The gap between the sexes is a constant 166 kcal at the same height, weight and age: the equation reflects that men carry more muscle on average.

Every row comes from the calculator on this page, in kcal a day.
Age	Man, 75 kg, 178 cm	Woman, 62 kg, 165 cm
20	1,768	1,390
30	1,718	1,340
40	1,668	1,290
50	1,618	1,240
60	1,568	1,190
70	1,518	1,140

From BMR to daily expenditure

Daily expenditure is BMR multiplied by an activity factor. For a 30-year-old man with a BMR of 1,718 kcal it runs from 2,061 kcal when sedentary to 3,263 when extremely active.

A man of 30, 75 kg, 178 cm. Daily expenditure comes from this site's calorie calculator; the share is BMR divided by expenditure.
Activity	Factor	Daily expenditure, kcal	BMR share
Sedentary	1.2	2,061	83%
Lightly active	1.375	2,362	73%
Moderately active	1.55	2,662	65%
Very active	1.725	2,963	58%
Extremely active	1.9	3,263	53%

What this calculator shows

Your BMR in kilocalories a day
A base figure to multiply by an activity factor

What to keep in mind

Uses Mifflin-St Jeor, which outperforms the older Harris-Benedict equation for modern populations.
Body composition matters and the formula cannot see it — more muscle means a higher real BMR than predicted.

Where the numbers come from

Checked against the Mifflin–St Jeor equation (1990).

FAQs

What is the difference between BMR and TDEE?

BMR is rest only. TDEE adds movement, exercise and the energy spent digesting food: activity factors of 1.2 to 1.9 put 20 to 90 percent on top of BMR.

What is a typical BMR for a woman?

For a 30-year-old woman of 62 kg and 165 cm, 1,340 kcal a day. Every 10 kg adds 100 kcal and every 10 years takes off 50.

Can I raise my BMR?

Somewhat, mainly by adding muscle, though the effect is modest — roughly 13 kcal per kilogram of muscle per day.

Does BMR fall with age?

In the equation, yes: 5 kcal a day for every year. Pontzer and colleagues' measurements (Science, 2021) found that, adjusted for lean mass, metabolism barely changes from 20 to 60 and declines after 60. Resistance training helps keep the muscle, and the metabolism with it.

Why is an athlete's real BMR higher than predicted?

The equation knows the weight but not what it is made of. Muscle burns more energy than fat, so a trained person of the same mass has a higher BMR.

Should I ever eat at my BMR?

BMR is not a universal minimum intake: whether a calorie target is right depends on total expenditure, on getting enough nutrients and on your health, so a plan that low is one to agree with a doctor. For the man in the example it is 1,718 kcal against an expenditure of 2,362 — a deficit of over 600 kcal a day.

Worked example

From BMR to daily needs

Input: BMR of 1700 kcal, lightly active

Output: About 2340 kcal per day

Note: The multiplier for light activity is roughly 1.375. Sedentary would give 2040, moderately active 2635.

Useful links

All tools in Health calculators for weight, lab values and training

BMR Calculator

Result

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