How is BMR different from TDEE?

BMR is just the calories burned at rest. Total Daily Energy Expenditure (TDEE) includes your BMR plus the calories burned through physical activity and digestion (the thermic effect of food).

Why use the Mifflin-St Jeor Equation?

Clinical studies, including those endorsed by the Academy of Nutrition and Dietetics, have found the Mifflin-St Jeor equation to be the most reliable and accurate formula for estimating resting metabolic rate in healthy adults.

Does BMR decrease with age?

Yes. As we age, we naturally lose lean muscle mass and hormonal changes occur. This lowers our resting metabolism, which is why calorie needs naturally decrease as we get older.

How is BMR different from TDEE?

BMR is just the calories burned at rest. Total Daily Energy Expenditure (TDEE) includes your BMR plus the calories burned through physical activity and digestion (the thermic effect of food).

Why use the Mifflin-St Jeor Equation?

Clinical studies, including those endorsed by the Academy of Nutrition and Dietetics, have found the Mifflin-St Jeor equation to be the most reliable and accurate formula for estimating resting metabolic rate in healthy adults.

Does BMR decrease with age?

Yes. As we age, we naturally lose lean muscle mass and hormonal changes occur. This lowers our resting metabolism, which is why calorie needs naturally decrease as we get older.

BMR Calculator

Calculate your Basal Metabolic Rate (BMR) - the number of calories your body needs to accomplish its most basic (basal) life-sustaining functions.

Calculation Tool

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Understanding Your Basal Metabolic Rate (BMR)

What is Basal Metabolic Rate?

Your Basal Metabolic Rate (BMR) represents the absolute minimum number of calories your body requires to perform its most fundamental life-sustaining functions while at complete rest. This includes breathing, circulation, cell production, and nutrient processing.

In almost all humans, BMR accounts for the vast majority (about 60% to 75%) of your Total Daily Energy Expenditure (TDEE). Knowing this number is the critical first step before building any weight loss, maintenance, or muscle-building nutritional plan.

How It Works (The Formula)

Our calculator uses the Mifflin-St Jeor equation, widely regarded by the Academy of Nutrition and Dietetics as the most accurate predictive equation for healthy adults:

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

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

This formula takes into account your biological sex, age, height, and weight to closely estimate your resting caloric burn. Note that having a high amount of lean muscle mass will result in a slightly higher actual BMR than predicted.

Data Sources & Methodology

Academy of Nutrition and Dietetics: Endorsement of the Mifflin-St Jeor equation for basal metabolism.
National Health Service (NHS): Guidelines on resting metabolism and safe caloric intake baselines.
Scientific Validation: Formula published by M.D. Mifflin and S.T. St Jeor in the American Journal of Clinical Nutrition.