Health Calculators

BMR Calculator

Calculate your basal metabolic rate based on well-known formulas with this online calculator.

BMR calculator

kg
cm
years
Gender
Man
Woman

The Mifflin St Jeor equation

kcal/day

Table of contents

What is basal metabolic rate (BMR)?
Basic formula for BMR
Mifflin-St Jeor Equation:
Revised Harris-Benedict Equation:
Katch-McArdle formula
BMR tests
New findings

What is basal metabolic rate (BMR)?

Basal metabolic rate means the number of calories your body needs to stay alive and keep its organs functional. The best way to calculate BMR is by using a machine dedicated for this purpose, like an InBody Measurement. It has the same idea as looking how much gasoline car burns when its idling with the engine on.
Normally BMR is measured under very restrictive circumstances while you are awake. To get accurate BMR reading, you need to be totally restful during the test. Basal metabolism is the largest factor in a person's total calorie need for a day. The daily calorie need is usually BMR multiplied with a factor from 1.2 to 1.9.

Basic formula for BMR

If you do not have access to one of the machines to calculate BMR, you can multiply your body weight in kilograms by 20. For example:
BMR = 80kg x 20 = 1600 calories
Better way to calculate BMR is to use some formula, such as The Mifflin St Jeor equation. Using this formula you get more accurate calculation of BMR. There are also other BMR formulas around there.
Read about The Mifflin St Jeor equation

Mifflin-St Jeor Equation:

Man:
BMR = 10W + 6.25H - 5A + 5
Woman:
BMR = 10W + 6.25H - 5A - 161

Revised Harris-Benedict Equation:

Man:
BMR = 13.397W + 4.799H - 5.677A + 88.362
Woman:
BMR = 9.247W + 3.098H - 4.330A + 447.593

Katch-McArdle formula

BMR = 370 + 21.6(1 - F)W
in which:
W = kg
H = cm
A = years
F = body fat %

BMR tests

Online tests and calculators for BMR are not always very accurate. Best result for BMR you will get by going to a physical measurement with a proper device, such as InBody measurement.

New findings

In 2005 one study showed that there is still a 26% unknown variances in BMR between people, even when all factors are controlled. Therefore BMR is not perfect measurement. Nevertheless BMR gives you a good reference point about your calorie burning, especially if you are an average person.

John Cruz
Article author
John Cruz
John is a PhD student with a passion to mathematics and education. In his freetime John likes to go hiking and bicycling.

BMR Calculator English
Published: Tue Jul 27 2021
Latest update: Mon Oct 18 2021
In category Health calculators
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