CalcArcade.

BMR Calculator

Enter your sex, age, weight and height. You get your basal metabolic rate (BMR) from two standard equations, and a third if you add your body fat percentage.

Your numbers

Result

Estimate for information only, not professional advice. Last reviewed .

How we calculate it

BMR is the energy your body uses at complete rest. The Mifflin-St Jeor equation (1990) is 10 × weight in kg + 6.25 × height in cm − 5 × age + 5 for men, and the same with − 161 instead of + 5 for women. For a 30 year old man of 80 kg and 180 cm that is 800 + 1,125 − 150 + 5 = 1,780 kcal a day.

The revised Harris-Benedict equation (Roza and Shizgal, 1984) is 88.362 + 13.397 × kg + 4.799 × cm − 5.677 × age for men, and 447.593 + 9.247 × kg + 3.098 × cm − 4.330 × age for women. The Katch-McArdle equation uses lean body mass instead: 370 + 21.6 × lean mass in kg, where lean mass is your weight times (1 − body fat percentage).

Assumptions and limits

  • This is an estimate for general information. It is not medical advice and cannot replace a conversation with a doctor or dietitian.
  • The equations are for adults, ages 18 to 100. They estimate an average person of your size, and a real metabolism can be noticeably higher or lower.
  • Katch-McArdle is only shown if you enter a body fat percentage, and it is only as good as that number.

Frequently asked questions

What is BMR?

Basal metabolic rate is the number of calories your body needs each day just to stay alive at rest, for breathing, circulation and keeping cells working. It does not include movement or exercise.

Which BMR equation is best?

None is exact. Studies have often found Mifflin-St Jeor to be closer than the older Harris-Benedict equations for many adults, and Katch-McArdle can suit people who know their body fat. Comparing them gives a sense of the range.

Is BMR the number of calories I should eat?

No. BMR is what you burn at rest. Your daily needs are higher because of activity. The calorie calculator multiplies your BMR by an activity factor to estimate that.

Related calculators

Worked example (a fixed example using the starting numbers, it does not change as you type)

Inputs: Units = US (pounds, feet and inches); Sex = Male; Age (years) = 30; Weight (pounds) = 176; Height: feet = 5; Height: inches = 11.

  • BMR (Mifflin-St Jeor) 1,780 kcal per day
  • BMR (Harris-Benedict, revised) 1,853 kcal per day

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Last reviewed: . Formulas and assumptions are described on our methodology page. For information only; not professional advice.