BMR Calculator

حاسبة معدل الأيض BMR

Find out how many calories your body needs a day at complete rest, using three well-known formulas.

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Result

Enter your age, weight and height.

Basal metabolic rate is the energy needed for vital functions only: breathing, circulation and body temperature. It's the starting point for daily calorie needs.

We recommend Mifflin–St Jeor, the most accurate for most adults in comparative studies. If you know your body-fat percentage reliably, Katch–McArdle is a good option.

Formulas used

Mifflin–St Jeor (1990): male = 10 × weight + 6.25 × height − 5 × age + 5; female: same − 161.
Revised Harris–Benedict (Roza & Shizgal 1984): male = 88.362 + 13.397 × W + 4.799 × H − 5.677 × A; female = 447.593 + 9.247 × W + 3.098 × H − 4.330 × A.
Katch–McArdle: 370 + 21.6 × lean body mass, where lean mass = weight × (1 − body fat).

Units

Weight in kg, height in cm, age in years
Result in kcal per day

Formulas are for adults. Individual error can be 10% or more. This is an estimate, not a medical assessment.

Worked examples

Man, 30, 70 kg, 175 cm

Mifflin: 1,649 kcal. Revised Harris–Benedict: 1,696 kcal. With 15% body fat, Katch–McArdle: 1,655 kcal.

Woman, 25, 60 kg, 165 cm

Mifflin: 600 + 1,031.25 − 125 − 161 = 1,345 kcal a day.

Frequently asked questions

BMR vs daily calories?

BMR is complete rest only. Your total daily need is higher because it includes movement, activity and digestion. Use the Calorie Calculator for that.

Which formula should I choose?

Mifflin–St Jeor for most people. Katch–McArdle if your body fat is known reliably, especially for athletes.

Why do the formulas differ?

They come from studies of different groups. Differences are usually 50–100 kcal.

Content last reviewed: November 1, 2026