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Health and fitness formula

How to calculate BMR

BMR estimates resting calories burned per day before activity.

See the formulaOpen calculator
Direct answer
Formula
BMR = 10W + 6.25H - 5A + S

Use the table below to match each symbol with the right input. Keep units consistent before you start.

BMR formula
Start here when you only need the equation and variable names.
Formula
BMR = 10W + 6.25H - 5A + S

BMR estimates resting calories burned per day before activity.

Variable meanings
Check each symbol, meaning, and unit before you calculate.
SymbolNameDescriptionUnit
WWeightBody weight.kg
HHeightBody height.cm
AAgeAge in years.years
SSex constant5 for male, -161 for female in the Mifflin-St Jeor equation.Depends on inputs
When to use this formula
Check that your situation matches the formula before you trust the result.
  • Treat it as a calorie planning estimate when age, height, weight, and sex are known.
Step-by-step method
Follow these steps when you are solving it by hand.
  1. 1Convert weight to kilograms.
  2. 2Convert height to centimeters.
  3. 3Use S = 5 for male and S = -161 for female in this calculator.
  4. 4Calculate the expression and round the result.
Examples
These sample numbers show the order of operations and units.
Male estimate
W
80 kg
H
180 cm
A
35
S
5
  1. 1.BMR = 10 * 80 + 6.25 * 180 - 5 * 35 + 5
  2. 2.BMR = 800 + 1125 - 175 + 5
  3. 3.BMR = 1755
Result
The BMR estimate is 1,755 calories per day.
Female estimate
W
65 kg
H
165 cm
A
30
S
-161
  1. 1.BMR = 10 * 65 + 6.25 * 165 - 5 * 30 - 161
  2. 2.BMR = 650 + 1031.25 - 150 - 161
  3. 3.BMR = 1370.25
Result
The BMR estimate is about 1,370 calories per day.
Mistakes to avoid
Small input or unit errors can change the answer a lot.
  • Treating the bmr result as a diagnosis or a personal training plan.
  • Mixing inches, centimeters, pounds, and kilograms without converting first.
  • Using stale measurements after weight, activity, or training level changes.
  • Ignoring the method assumptions behind the estimate.
Open the BMR Calculator
Open the calculator for the answer without rewriting the formula.

Enter your values in the related calculator, then compare the output with the hand method above.

Open BMR Calculator
FAQs
Short answers for common formula questions.
Is the BMR formula a medical test?

No. It gives an estimate from a few inputs. Treat it as a planning or screening number, and ask a qualified clinician about symptoms, medication, pregnancy, eating disorders, or medical conditions.

Why can my BMR result differ from a wearable or lab test?

Different methods use different assumptions. Small measurement changes, activity estimates, and rounding can move the result.

Can I use the BMR Calculator instead?

Yes. The BMR Calculator handles the arithmetic and helps catch unit conversion mistakes.