BMR Calculator

Estimate your basal metabolic rate (BMR) with two standard equations.

Years.

Weight
Height
Result—

Enter your values and calculate to see the result.

Formula used

Mifflin-St Jeor:
  men:   10·weight(kg) + 6.25·height(cm) − 5·age + 5
  women: 10·weight(kg) + 6.25·height(cm) − 5·age − 161
Harris-Benedict:
  men:   66.5 + 13.75·weight + 5.003·height − 6.755·age
  women: 655.1 + 9.563·weight + 1.850·height − 4.676·age
(weight kg, height cm)
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Worked example

Man, 35 yrs, 80 kg, 180 cm:

Mifflin-St Jeor = 10×80 + 6.25×180 − 5×35 + 5 = 1,730 kcal/day

Harris-Benedict = 66.5 + 13.75×80 + 5.003×180 − 6.755×35 = 1,768 kcal/day

Frequently asked questions

What is BMR?

Basal metabolic rate is the number of calories your body burns at complete rest, just to keep you alive — breathing, circulation, and cell repair. It excludes all activity.

Which equation is better, Mifflin-St Jeor or Harris-Benedict?

Mifflin-St Jeor is generally more accurate for modern populations and is the one most often recommended. Harris-Benedict tends to run a little high. The calculator shows both so you can compare.

How do I use BMR to plan my calories?

Multiply BMR by your activity factor to get TDEE (see the calorie calculator), then add a deficit to lose weight or a surplus to gain. BMR itself is the floor you usually want to stay above.

Why does muscle raise BMR?

Muscle tissue is metabolically active even at rest, so more muscle means more calories burned. That is why two people of the same weight can have different BMRs.

Does BMR change over time?

Yes. It tends to fall with age and muscle loss, and rise with muscle gain. Re-check periodically if your body or routine changes significantly.