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How do I calculate my BMR (basal metabolic rate)?

Short answer

BMR is the calories your body burns at complete rest, commonly estimated with the Mifflin-St Jeor equation from your weight, height, age and sex. A free BMR calculator applies the equation in your browser and returns an estimated resting calorie figure. It is a screening estimate, not medical advice.

The Mifflin-St Jeor equation

A widely used BMR estimate is the Mifflin-St Jeor equation: 10 x weight in kg, plus 6.25 x height in cm, minus 5 x age in years, then plus 5 for men or minus 161 for women. It gives the approximate calories your body uses at rest to keep basic functions running. A calculator handles the arithmetic and lets you switch between metric and imperial inputs.

What BMR is for

BMR is the foundation for estimating total daily calorie needs: multiply it by an activity factor to get TDEE. On its own it tells you roughly how many calories you would burn lying still all day. Because the equation is a population average, individual metabolism varies, so treat the number as a baseline and verify against how your body actually responds, or with a professional for any health plan.

Frequently asked questions

What is the Mifflin-St Jeor formula?

10 x weight in kg + 6.25 x height in cm - 5 x age + 5 for men, or - 161 for women. It estimates resting calorie burn.

How is BMR different from TDEE?

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

Is BMR the same for everyone of my weight?

No. Height, age and sex all change it, and individual metabolism varies, so the equation is an estimate rather than an exact figure.

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