BMR Calculator

This BMR calculator estimates your basal metabolic rate (BMR) and the number of calories you need per day based on your activity level.

Unit Type:

Height:

ft
in
cm

Weight:

lb
kg
%
BMR  =  

Daily Calorie Needs:

Activity Level Calorie
Sedentary (Little or No Exercise):
Lightly Active (1-3 times/week):
Moderately Active (3-5 times/week):
Very Active (6-7 times/week):
Extra Active (Very Intense Exercise Daily, or Physical Job):

What is BMR?

BMR (Basal Metabolic Rate) is the number of calories your body needs each day just to stay alive while at complete rest. It represents the energy your body uses to perform essential functions such as:

  • Blood Circulation
  • Breathing
  • Maintaining body temperature
  • Repairing cells and tissues
  • Supporting brain activity

In simple terms, BMR is the minimum number of calories your body burns if you were resting all day without any physical activity. Also, it is commonly used as the starting point for calculating Total Daily Energy Expenditure (TDEE).

Factors That Affect BMR

The following factors influence a person's basal metabolic rate:

  • Age: Metabolism generally slows as people get older.
  • Gender: Men often have a higher BMR than women because they typically have more muscle mass.
  • Body Size and Weight: Larger bodies require more energy to support basic body functions.
  • Muscle Mass: Muscle burns more calories than fat, even at rest.
  • Genetics: Some people naturally have faster or slower metabolisms.
  • Health Conditions: Hormonal issues, such as thyroid disorders, can affect metabolic rate.

How Does the BMR Calculator Work

  1. Select the unit type as needed. The tool supports imperial (US or UK) and metric units.
  2. Select your age and gender.
  3. Enter your height and weight based on the selected unit type.
  4. Choose the BMR formula. The tool allows you to calculate BMR using three formulas. Mifflin-St Jeor, Harris-Benedict (Revised), and Katch-McArdle.
  5. Enter your body fat if you calculate BMR using the Katch-McArdle formula.
  6. After inputting all the values, press the 'Calculate' button to generate results.
  7. Lastly, the tool returns your Basal Metabolic Rate (BMR) and daily calorie needs according to your activity level.
  8. For new BMR calculations, press the 'Reset' button.

How to Calculate BMR

The BMR is calculated using the following formulas:

1. Mifflin-St Jeor:

For Men:

10 × weight(kg) + 6.25 × height(cm) - 5 × age + 5

For Women:

10 × weight(kg) + 6.25 × height(cm) - 5 × age - 161

2. Harris-Benedict Equation (Revised):

For Men:

13.397 × weight(kg) + 4.799 × height(cm) - 5.677 × age + 88.362

For Women:

9.247 × weight(kg) + 3.098 × height(cm) - 4.330 × age - 447.593

3. Katch-McArdle:

For Men and Women:

370 + 21.6 × (1 - body fat(%) ÷ 100) × weight(kg)