BMR calculator
The calories your body uses at rest, by the three formulas dietitians use, and what that becomes once you move.
Daily calories by activity
Your BMR multiplied by the standard activity factors.
| Activity level | Factor | Calories a day |
|---|---|---|
| Sedentary Little or no exercise, desk job | × 1.2 | — |
| Lightly active Exercise 1–3 days a week | × 1.375 | — |
| Moderately active Exercise 3–5 days a week | × 1.55 | — |
| Very active Hard exercise 6–7 days a week | × 1.725 | — |
| Extra active Physical job or training twice a day | × 1.9 | — |
How it’s worked out
- Your numbers
- BMR
The formulas
- Mifflin-St Jeor: 10 × kg + 6.25 × cm − 5 × age + 5 for men, − 161 for women.
- Revised Harris-Benedict: men 13.397 × kg + 4.799 × cm − 5.677 × age + 88.362; women 9.247 × kg + 3.098 × cm − 4.330 × age + 447.593.
- Katch-McArdle: 370 + 21.6 × lean body mass (kg).
Questions people ask
What is BMR?
Basal metabolic rate is the energy your body uses at complete rest to keep you alive: breathing, circulation, cell repair and body temperature. It is the floor of your daily calorie needs.
Why do the three formulas disagree?
Each was fitted to a different group of people. Mifflin-St Jeor (1990) is the most accurate for most adults today. Revised Harris-Benedict (1984) tends to run a little higher. Katch-McArdle uses lean body mass instead of age and sex.