Calculate the calories your body burns at rest.
Mifflin-St Jeor: men 10 × kg + 6.25 × cm − 5 × age + 5; women … − 161. A 30-year-old man, 75 kg and 175 cm, has a BMR of 1,699 kcal.
Your basal metabolic rate (BMR) is the energy your body uses to stay alive at rest — breathing, circulation, temperature control and cell repair. It makes up roughly 60–70% of the calories most people burn. Enter your sex, age, height and weight to see your BMR with the Mifflin-St Jeor and revised Harris-Benedict equations; add your body-fat percentage for the Katch-McArdle estimate.
BMR is the starting point for working out how much to eat. Multiply by an activity factor to get your daily needs with the TDEE Calculator, then set a goal with the Calorie Calculator. For lean mass see the Lean Body Mass Calculator.
The calculator applies the standard published formulas step by step.
| Item | Value |
|---|---|
| BMR per hour | 71 kcal |
| BMR in kilojoules | 7,108 kJ |
| BMI | 24.5 kg/m² |
| Formula | BMR |
|---|---|
| Mifflin-St Jeor (most widely recommended) | 1,699 kcal |
| Revised Harris-Benedict | 1,763 kcal |
| Case | BMR |
|---|---|
| Age 25 | 1,724 kcal a day |
| Age 30 | 1,699 kcal a day |
| Age 45 | 1,624 kcal a day |
| Age 60 | 1,549 kcal a day |
| Weight 90 kg | 1,849 kcal a day |
The number of calories your body needs at complete rest to maintain basic life functions.
Mifflin-St Jeor is generally the most accurate for the general population; Katch-McArdle is better if you know your body fat, especially for lean or muscular people.
RMR (resting metabolic rate) is measured under less strict conditions and is usually slightly higher than BMR. The terms are often used interchangeably.
Building muscle, sleeping well and not crash-dieting help. BMR also falls with age and weight loss.
No. Your maintenance calories also include movement and digestion — see the TDEE Calculator.
On average men have more lean mass and less fat, and muscle burns more energy at rest than fat.
It uses the published formula: BMR (men) = 10W + 6.25H − 5A + 5 BMR (women) = 10W + 6.25H − 5A − 161 The full method and a worked example are shown on this page.
No. The calculator gives general estimates for information and education. It cannot diagnose or treat anything, so please speak to a doctor or qualified professional about your own health.
Yes. Choose centimetres or feet and inches for height, and kilograms, pounds or stone for weight; the results are converted for you.
No. Everything is calculated in your browser and nothing you enter is uploaded or saved.
