WorldCalcs

BMR Calculator

Basal Metabolic Rate in kcal/day using the Mifflin-St Jeor equation.

Reviewed by the WorldCalcs team · Methodology · Last reviewed: June 2026

Estimated BMR

1 780 kcal/day

Mifflin-St Jeor: 10×kg + 6.25×cm − 5×age + (+5 male / −161 female).

This is a general estimate, not medical or nutritional advice. Speak to a professional before changing your diet. See our Disclaimer.

What is BMR?

Your basal metabolic rate (BMR) is the number of calories your body burns at complete rest, just to keep you alive: breathing, circulating blood and maintaining temperature. It is the largest part of your daily energy use, before any movement or exercise is added, so it is the starting point for working out how many calories you need each day. This calculator uses the Mifflin-St Jeor equation, the formula most dietitians regard as the most accurate for the general population.

How BMR is calculated

The Mifflin-St Jeor equation is: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years), then plus 5 for men or minus 161 for women. To turn BMR into the calories you actually burn in a day, multiply it by an activity factor; that step gives your total daily energy expenditure (TDEE). See our Calorie Calculator.

Example

A 30-year-old man who weighs 80 kg and is 180 cm tall has a BMR of 10 × 80 + 6.25 × 180 − 5 × 30 + 5 = 800 + 1125 − 150 + 5 = 1 780 calories per day. A 30-year-old woman at 65 kg and 165 cm has 10 × 65 + 6.25 × 165 − 5 × 30 − 161 = 1 370 calories per day.

All calculations happen in your browser. Nothing is sent, stored, or tracked.

Results are estimates and may contain errors — for general information only, not professional advice. Always verify before relying on them. Disclaimer

How to use

Enter your sex, age, weight and height (metric or imperial). The tool converts to kg/cm internally and applies the Mifflin-St Jeor equation.

BMR is the energy you would use in a day if you did nothing but rest. To estimate your full daily calorie needs, use the calorie calculator (TDEE).

Frequently asked questions

What is the difference between BMR and TDEE?+

BMR is calories burned at rest; TDEE is BMR multiplied by an activity factor to include daily movement and exercise.

Which BMR formula is most accurate?+

The Mifflin-St Jeor equation is widely considered the most accurate for most people; the older Harris-Benedict tends to run slightly high.

Why do men and women have different BMR?+

On average men carry more muscle, which burns more energy, so the formula adds 5 for men and subtracts 161 for women.

Does BMR change with age?+

Yes; it generally declines with age, which is why age is in the formula.

Can I lose weight by eating below my BMR?+

Eating below BMR for long is not recommended; weight management is better based on TDEE. See our Calorie Calculator.

How do I use my BMR?+

Multiply it by an activity factor to get your daily calorie needs (TDEE).

Does muscle increase BMR?+

Yes; more muscle raises resting energy use, which is partly why strength training helps.

Is BMR the same as metabolism?+

It is the resting part of your metabolism, the baseline before activity is added.

References

  • Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition, 1990.

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