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BMR Calculator

Calculate your Basal Metabolic Rate and Total Daily Energy Expenditure to understand how many calories your body needs each day.

What is BMR?

Your Basal Metabolic Rate (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. It represents the minimum energy your body requires to stay alive.

Your Total Daily Energy Expenditure (TDEE) adds the calories burned through daily activities and exercise on top of your BMR, giving you the total calories you need each day to maintain your current weight.

About the Formulas

Mifflin-St Jeor

Developed by Mifflin et al. (1990) and validated by the American Dietetic Association in 2005 as the most accurate BMR equation for most individuals, predicting BMR within 10% for 82% of people studied. Widely recommended by dietitians and nutrition professionals as the go-to formula.

Harris-Benedict

Originally published in 1919 by James Arthur Harris and Francis Gano Benedict, later revised by Roza and Shizgal in 1984. One of the oldest and most well-known BMR equations, though it tends to slightly overestimate calorie needs compared to more modern formulas.

Katch-McArdle

Accounts for lean body mass, making it more accurate for athletes and individuals who know their body fat percentage. Especially useful for lean or muscular individuals whose metabolic rate is better predicted by fat-free mass than total body weight alone.

Track Your Progress with Gymscore

Understanding your metabolism is step one. Gymscore helps you take the next step with AI-powered workout tracking and form analysis to optimize every calorie you burn.