BMR Calculator (Mifflin-St Jeor)
Calculate your Basal Metabolic Rate (BMR) to estimate how many calories your body needs at rest. A vital metric for establishing baseline nutritional needs.
Basal Metabolism Explained
Basal Metabolic Rate (BMR) represents the minimum amount of energy your body requires to perform basic life-sustaining functions, such as breathing, circulation, and cell production. It accounts for about 60-75% of your total daily energy expenditure (TDEE). Understanding your BMR is the first step in creating any effective nutrition or fitness plan.
BMR vs. TDEE
While BMR is your energy at rest, TDEE includes BMR plus the energy burned during physical activity and digestion. To find TDEE, you multiply BMR by an activity factor.
Factors Affecting BMR
Lean muscle mass is the biggest factor; the more muscle you have, the higher your BMR. Age, genetics, and hormone levels also play significant roles.
The Mifflin-St Jeor Equation
MODERN SCIENTIFIC STANDARD
Men: 10(W) + 6.25(H) - 5(A) + 5
Women: 10(W) + 6.25(H) - 5(A) - 161
Developed in 1990, this formula is considered more accurate than the older Harris-Benedict equation. (W = Weight in kg, H = Height in cm, A = Age in years).
BMR Reference Estimates
Demographic Profile Estimated BMR Male, 25yr, 70kg, 180cm 1,710 kcal Female, 25yr, 60kg, 165cm 1,370 kcal Male, 40yr, 85kg, 180cm 1,770 kcal Female, 40yr, 65kg, 165cm 1,345 kcal Male, 60yr, 75kg, 175cm 1,550 kcal Basal Metabolic Rate FAQ