Boneyard Tools

BMR Calculator

Find your basal metabolic rate, the calories your body burns at rest. Enter your weight, height, age and sex and we apply the Mifflin-St Jeor equation, the standard most dietitians use today.

How to use the BMR calculator

  1. Pick metric (kg, cm) or imperial (lb, in) units.
  2. Enter your weight, height, age and select your sex.
  3. Read your BMR in calories per day, then multiply by an activity factor for full daily needs.

Examples

Man, 80 kg, 180 cm, 30 years

weight 80 kg, height 180 cm, age 30, male
1780 kcal/day

Woman, 80 kg, 180 cm, 30 years

weight 80 kg, height 180 cm, age 30, female
1614 kcal/day

Frequently asked questions

What is BMR?

Basal metabolic rate is the number of calories your body uses at complete rest to run vital functions like breathing, circulation and cell repair. It is the largest part of most people's daily calorie burn and excludes any physical activity.

What equation does this use?

It uses the Mifflin-St Jeor equation: 10 times weight in kg plus 6.25 times height in cm minus 5 times age, then plus 5 for men or minus 161 for women. Imperial inputs are converted to metric first.

Mifflin-St Jeor or Harris-Benedict?

Both estimate BMR, but the revised Harris-Benedict tends to overestimate for many people. Research has found Mifflin-St Jeor more accurate for the general population, which is why it is the modern default.

What is the difference between BMR and TDEE?

BMR is your calorie burn at rest. Total daily energy expenditure (TDEE) is BMR multiplied by an activity factor, roughly 1.2 for sedentary up to about 1.9 for very active, so it reflects everything you do in a day.

How do I use my BMR for weight goals?

Calculate your TDEE from your BMR, then eat below it to lose weight or above it to gain. A deficit or surplus of about 500 calories a day changes weight by roughly half a kilogram per week.

Is my data sent anywhere?

No. The calculation runs entirely in your browser. Your weight, height, age and sex never leave your device.

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