Basal Metabolic Rate (BMR) Calculator
＋More features: calculate from body-fat percentage, change by age group
If you know your body-fat percentage (compare two methods)
Enter the body-fat percentage from a body-composition scale to also calculate with the lean-body-mass-based Katch-McArdle formula and compare it with the method above (weight and other values are taken from the form above).
How much does it drop with age?
Keeping the sex and weight above, this lists the basal metabolic rate for each adult age group.
Enter just your age, sex and weight to find out how many calories your body burns per day even at complete rest (basal metabolic rate). It is calculated with the official reference values of Japan's Ministry of Health, Labour and Welfare — the basis used in Japanese nutrition guidance. This number is the foundation for deciding the minimum you should eat when dieting, and a good first step in managing your meals.
How to use
- Enter your age as a whole number.
- Select your sex.
- As soon as you enter your weight in kilograms, your basal metabolic rate appears below — no button needed.
How it is calculated
Basal metabolic rate (kcal/day) = basal metabolism reference value (kcal/kg body weight/day) × weight (kg)
The reference values are the age-group and sex-specific values from the Japanese Ministry of Health, Labour and Welfare's “Dietary Reference Intakes for Japanese (2015 edition)”.
| Age | Men | Women |
|---|---|---|
| 1–2 | 61.0 | 59.7 |
| 3–5 | 54.8 | 52.2 |
| 6–7 | 44.3 | 41.9 |
| 8–9 | 40.8 | 38.3 |
| 10–11 | 37.4 | 34.8 |
| 12–14 | 31.0 | 29.6 |
| 15–17 | 27.0 | 25.3 |
| 18–29 | 24.0 | 22.1 |
| 30–49 | 22.3 | 21.7 |
| 50–69 | 21.5 | 20.7 |
| 70 and over | 21.5 | 20.7 |
Sources (primary information)
- Ministry of Health, Labour and Welfare (Japan), e-Health Net “Aging and energy metabolism” (reference value table from the Dietary Reference Intakes for Japanese, 2015 edition) — in Japanese
https://kennet.mhlw.go.jp/information/information/food/e-07-002.html (accessed July 18, 2026)
Assumptions and notes
- The basal metabolic rate is the minimum energy your body uses at rest. Your total daily energy expenditure is larger, depending on how active you are (roughly estimated as BMR × physical activity level).
- The reference values are based on an average build (reference weight), so muscle mass and body composition cause individual differences.
- Do not make decisions about dieting or other health management from numbers alone — consult a doctor or registered dietitian.
Frequently asked questions
If I eat exactly my basal metabolic rate, will my weight stay the same?
No. Your total daily energy expenditure adds your activity on top of the basal metabolic rate, so it is larger (as a guide: BMR × physical activity level 1.5–2.0).
The result differs from other websites.
There are several formulas for estimating basal metabolism (Harris-Benedict and others). This tool multiplies the reference value from Japan's Dietary Reference Intakes by your weight; a different formula can change the result by several tens to about a hundred kcal.
How can I raise my basal metabolism?
The age-related decline in basal metabolism is mainly attributed to the loss of lean mass such as muscle, so an exercise habit that maintains or increases muscle is the commonly recommended countermeasure (see the source page).