BMR calculator
BMR is the energy your body uses at rest to keep you alive. A 30-year-old woman who is 1.70 m tall and weighs 65 kg burns about 1,400 kcal a day at rest.
- Checked on thousands of cases
- Sources: Mifflin et al. (1990), FAO/WHO/UNU (2001)
- Updated November 2, 2026
Your BMR
5,900 kJ per day
An estimate for healthy adults. Not suitable during pregnancy or breastfeeding, or in case of illness.
How it works
Formula: BMR = 10 × kg + 6.25 × cm − 5 × age + 5 (men) or − 161 (women)
The calculator uses the Mifflin-St Jeor equation (1990), built from measurements on healthy adults aged 19 to 78: 10 × weight in kg + 6.25 × height in cm − 5 × age in years, then + 5 for men or − 161 for women. Strictly, it estimates resting energy expenditure, which is very close to the basal metabolic rate and is commonly used in its place. It is an average for people of your size, age and sex: individual values can differ, and it does not account for body composition, illness, pregnancy or breastfeeding.
BMR by weight at 5′ 7″, age 30 (kcal/day)
| Weight | Woman | Man |
|---|---|---|
| 110 lb | 1,250 | 1,420 |
| 130 lb | 1,340 | 1,510 |
| 150 lb | 1,430 | 1,600 |
| 170 lb | 1,520 | 1,690 |
| 190 lb | 1,610 | 1,780 |
| 210 lb | 1,710 | 1,870 |
Frequently asked questions
How do I calculate my BMR by hand?
For a 40-year-old man, 180 cm and 80 kg: 10 × 80 + 6.25 × 180 − 5 × 40 + 5 = 800 + 1,125 − 200 + 5 = 1,730 kcal a day.
What is the difference between BMR and daily calorie needs?
BMR is what you burn at complete rest. Your daily needs add the energy of all your activities, so they are higher: from 1.40–1.69 times your BMR for a light lifestyle to 2.00–2.40 for a vigorous one.
Why does BMR decrease with age?
The equation removes 5 kcal per year of age, reflecting the average loss of lean mass over time. Staying active and keeping muscle limits that drop.
Is the result in calories or kilocalories?
In kilocalories (kcal), the 'calories' shown on food labels. The calculator also shows the value in kilojoules (1 kcal = 4.184 kJ).