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).

What is BMR?

Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest to keep essential functions going — breathing, circulation and cell repair. It is the energy you would use in a day if you did nothing but rest.

How BMR is calculated

This tool uses the Mifflin-St Jeor equation: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 for men, or − 161 for women. Example: a 30-year-old man weighing 80 kg at 180 cm has a BMR of about 1 780 kcal per day.

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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 BMR?+

The calories your body burns at rest to maintain basic functions like breathing and circulation.

How is BMR calculated?+

With the Mifflin-St Jeor equation, which uses weight, height, age and sex (men +5, women −161).

What is the difference between BMR and TDEE?+

BMR is your at-rest calorie burn; TDEE adds the calories burned through daily activity and exercise.

Why does BMR decrease with age?+

Resting energy use tends to fall as we age, so the equation subtracts 5 calories for each year of age.

Is the Mifflin-St Jeor equation reliable?+

It is one of the most accurate predictive BMR equations for healthy adults, though individual results vary.

Should I eat fewer calories than my BMR?+

Eating below your BMR is generally not recommended; base calorie goals on your TDEE instead.

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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