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Health & Fitness

BMR Calculator

Calculate your Basal Metabolic Rate - the number of calories your body burns at complete rest. Compare results from Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle formulas.

Personal Information

30 years
70 kg
170 cm

Your BMR

1,618

calories per day at rest

Formula Comparison

Mifflin-St Jeor

Most accurate for modern populations (1990)

1,618 cal
Harris-Benedict
1,672 cal

Daily Calories by Activity

Sedentary

Little or no exercise, desk job

1,941 cal
Lightly Active

Light exercise 1-3 days per week

2,224 cal
Moderately Active

Moderate exercise 3-5 days per week

2,507 cal
Very Active

Hard exercise 6-7 days per week

2,790 cal
Extra Active

Very hard exercise, physical job

3,073 cal

BMR is the number of calories your body needs to perform basic life-sustaining functions like breathing, circulation, and cell production while at complete rest.

How is BMR Calculated?

BMR can be calculated using several established formulas. Each has different accuracy depending on your body composition:

Mifflin-St Jeor

Most accurate for modern populations (1990)

Men: BMR=10×weightkg+6.25×heightcm−5×age+5\text{Men: } BMR = 10 \times weight_{kg} + 6.25 \times height_{cm} - 5 \times age + 5
Women: BMR=10×weightkg+6.25×heightcm−5×age−161\text{Women: } BMR = 10 \times weight_{kg} + 6.25 \times height_{cm} - 5 \times age - 161

Harris-Benedict

Men: BMR=88.362+13.397×w+4.799×h−5.677×age\text{Men: } BMR = 88.362 + 13.397 \times w + 4.799 \times h - 5.677 \times age
Women: BMR=447.593+9.247×w+3.098×h−4.330×age\text{Women: } BMR = 447.593 + 9.247 \times w + 3.098 \times h - 4.330 \times age

Katch-McArdle

Most accurate when body fat % is known

BMR=370+21.6×LBMkgBMR = 370 + 21.6 \times LBM_{kg}

Tips for Using Your BMR

  • 1BMR represents calories at complete rest - you'll burn more with any activity
  • 2Multiply BMR by your activity factor to get Total Daily Energy Expenditure (TDEE)
  • 3More muscle mass means higher BMR - strength training can boost metabolism
  • 4BMR naturally decreases with age, so recalculate periodically
  • 5Severe calorie restriction can lower BMR - avoid crash diets

Related Calculators

TDEE Calculator

Calculate your Total Daily Energy Expenditure to understand how many calories you burn each day.

Calorie Calculator

Find your daily calorie needs based on your age, gender, weight, and activity level.