How to use the BMR Calculator
- Choose your sex.
- Enter age, height in cm and weight in kg.
- Compare the Mifflin-St Jeor and Harris-Benedict results.
Formula used
W = weight in kg, H = height in cm, A = age in years.
Worked examples
| Person | Mifflin-St Jeor BMR |
|---|---|
| Man, 30, 175 cm, 75 kg | 1,699 kcal |
| Woman, 25, 165 cm, 60 kg | 1,345 kcal |
| Woman, 40, 160 cm, 70 kg | 1,339 kcal |
Can you raise your BMR?
Muscle burns more energy than fat, so strength training can raise BMR a little over time. BMR also falls slowly with age. To turn BMR into a daily target, use the Calorie Calculator.
Medical note: this tool gives general estimates for healthy adults. It is not a diagnosis. Talk to a doctor or registered dietitian before making big changes, especially if you are pregnant, under 18, an athlete or living with a health condition.
Frequently asked questions
What is a normal BMR?
For most adults it is between about 1,200 and 2,000 kcal a day, depending on size, age and sex.
Is BMR the same as RMR?
Almost. Resting metabolic rate (RMR) is measured under less strict conditions and is usually slightly higher, but the terms are often used interchangeably.
Which BMR formula is best?
Mifflin-St Jeor is usually recommended for healthy adults. If you know your body fat percentage, the Katch-McArdle formula can be more accurate for lean people.
Should I eat less than my BMR to lose weight?
No. Eating below your BMR for long periods is not recommended without medical supervision.
Why does BMR drop with age?
Mainly because people lose muscle mass as they age. Staying active helps slow this.
Our team builds and tests every tool by hand, checks each formula against official sources (IRS, HMRC, the Income Tax Department of India, CBSE, NHS, WHO) and reviews pages whenever rules change. Last reviewed on . Spotted a mistake? Tell us.