BMR Calculator

Your Basal Metabolic Rate is the energy your body uses at complete rest just to keep you alive.

How the Math Works

The BMR Calculator uses the Mifflin-St Jeor equation, a scientifically validated formula that estimates the calories your body burns at complete rest. For men, the formula is: BMR = 10 times your weight in kilograms plus 6.25 times your height in centimeters minus 5 times your age in years plus 5. For women, the same formula applies but subtracts 161 instead of adding 5. This equation accounts for the fundamental relationship between body mass, height, and age in determining metabolic needs, as these factors directly influence the energy required to maintain basic physiological functions like breathing and circulation.

Practical Applications

To use this calculator, simply enter your weight in kilograms (or convert from pounds by dividing by 2.2), your height in centimeters (or convert from inches by multiplying by 2.54), and your age in years. Select your gender from the dropdown menu, then click calculate. The result shows your Basal Metabolic Rate in calories per day, which represents the minimum energy needed for your body's essential functions while fasting and at rest. This baseline measurement is crucial for determining appropriate caloric intake goals.

Day-to-Day Use

Knowing your BMR empowers you to make informed decisions about nutrition and fitness planning. Your daily calorie needs are typically 20-40% higher than your BMR when factoring in activity levels, so this calculation helps establish a realistic starting point for weight management. Whether you're aiming to lose weight, maintain your current physique, or build muscle, understanding your metabolic baseline prevents extreme dietary approaches and ensures your caloric targets support sustainable health goals. This knowledge transforms guesswork into data-driven wellness decisions.

Worked example

Male, 70 kg, 175 cm, 30 yrs → 700 + 1,093.75 − 150 + 5 = 1,649 kcal/day.

FAQ