BMR Calculator

Basal Metabolic Rate

This BMR Calculator is a simple tool that helps you calculate how many calories your body needs if you were only to rest for the whole day.

General Settings

Imperial units
Example: 5.7
Example: 110


BMR --- kcal /day

What does BMR mean?

BMR stands for basal metabolic rate. This is the number of calories your body uses without any physical activity (for example, spending an entire day resting in bed). To put it simply, BMR is the amount of fuel your engine (body) burns while idling (resting).

In an idle state, your body still needs fuel to power your vital organs, like your brain, heart, lungs, liver, intestines, skin, and so on. The majority of people use about 70% of their total calorie expenditure for maintaining these vital organs. 10% of their calories are used to digest food, and 20% of calories are burned during physical activity. This means that most of your caloric intake is used to upkeep your organs at rest.

What is a BMR calculator?

Our BMR calculator uses your gender, age, height, and weight to estimate your basal metabolic rate. This calculation is made with the Mifflin-St. Jeor equation, which is considered more accurate than other formulas, such as the Harris-Benedict equation.

What is the purpose of a BMR calculator?

Our BMR calculator helps you understand how many calories you should consume daily to maintain your current body weight without physical activity. You can multiply your BMR by numbers ranging from 1.2 to 2.4, depending on your activity level, to get your TDEE (total daily energy expenditure). For example, multiplying by 1.2 would be ideal if you have a highly sedentary lifestyle–while multiplying by 2.4 would be ideal for pro athletes. Check out our TDEE calculator here to learn more.

What is the Mifflin-St. Jeor equation?

The Mifflin-St Jeor equation uses four variables to calculate your BMR. These variables are gender, age, height, and weight.

Here is what the Mifflin-St Jeor equation looks like:

  • • For women: 10W + 6.25H - 5A - 161 = BMR
  • • For men: 10W + 6.25H - 5A + 5 = BMR

How can this free BMR calculator help me with my Healthy Keto plan?

While counting calories is not the primary goal of Healthy Keto, knowing how much energy you use each day can help you stay on track with your weight loss goals. If you struggle to lose weight after becoming keto-adapted, you may need to lower your calorie intake by reducing your fat, carb, and protein consumption. Dr. Berg’s free BMR calculator helps you understand how much energy your body needs while at rest. If you want a more detailed look at your keto plan, try our free keto macros calculator here.