# BMR Calculator (Basal Metabolic Rate, Mifflin St Jeor Equation)

BMR Calculator is a simple tool that helps you calculate how many calories your body would need if you were only to rest for the whole day. Based on your age, height, weight and gender, the Basal Metabolic Rate Calculator will return your individual BMR score. Keep reading to find out what is BMR, how to calculate BMR, more about Mifflin St Jeor equation and other BMR formulas.

## What is BMR?

It’s the amount of energy your body needs to support vital body functions. Those include breathing, blood circulation, controlling body temperature, brain and nerve functions among others. Your BMR accounts for about 60 to 75% of calories you burn every day, depending on your lifestyle. BMR tends to get lower with aging and decrease in lean body mass (link). On the other hand increasing your muscle mass will most likely also increase your BMR.

## Basal Metabolic Rate Calculator

BMR Calculator stands for Basal Metabolic Rate Calculator. Metabolism is a set of chemical reactions happening in any body that maintain its living state. Or to make it simpler - process of turning food you consume into energy you will need to function properly. Knowing what your BMR is can help you evaluate the total number of calories you should provide to your body on a daily basis.

## How to calculate BMR - the BMR formula

There are multiple formulas used to calculate BMR. Nowdays, the **Mifflin-St Jeor equation** is believed to give the most accurate result and it's what we use in this calculator. This BMR formula is as follows:

`BMR = (10 * weight / 1kg + 6.25 * height / 1cm - 5 * age / 1 year + s) kcal / day`

, where s is +5 for males and -161 for females.

We also have calculators that determine your Basal Metabolic Rate based on other formulas. for a long time the most common way to calculate your Basal Metabolic Rate was with Harris-Benedict equation, was originally published back in 1919 and for over 70 years was considered the best BMR Formula available.

Later on it was replaced with another Basal Metabolic Rate formula that turned out to be even more accurate – Mifflin St Jeor Equation. Until today you can find Harris-Benedict Equation used in many BMR Calculators although it’s being slowly replaced with the new formula.

The third known equation is Katch-McArdle formula, used to tell the Resting Daily Energy Expenditure (RDEE).

Back in 1990 two scientists – Miffin and St Jeor – formed a new, more precise BMR Formula called since Mifflin St Jeor Equation. The equation looks as follows:

In our Basal Metabolic Rate Calculator we used the most commonly used Mifflin St Jeor Equation to give you the most accurate BMR score. Other useful calculators serving similar purposes are aforementioned Lean Body Mass Calculator, Resting Metabolic Rate calculator, Body Mass Index Calculator, Max Heart Rate Calculator and Bench Press Calculator.