BMR Calculator

Mifflin-St Jeor (1990) is generally considered more accurate for the general population and is the formula recommended by the Academy of Nutrition and Dietetics. It was validated with indirect calorimetry in a wide sample of adults. Harris-Benedict (1919, revised 1984) tends to slightly overestimate BMR, especially in overweight individuals. Showing both gives a realistic range rather than a single point estimate.

On average, men have a higher proportion of lean muscle mass compared to women of the same height and weight, partly because of testosterone's anabolic effect. Muscle tissue is more metabolically active than fat at rest, so a higher muscle-to-fat ratio raises BMR. The sex-specific constants in both formulas account for this average difference, though individuals vary widely.

Multiply your BMR by an activity factor: 1.2 (sedentary), 1.375 (lightly active, 1-3 workouts/week), 1.55 (moderately active, 3-5 workouts/week), 1.725 (very active, 6-7 workouts/week), 1.9 (super active). The result is your TDEE - the calories needed to maintain your current weight. Subtract to lose, add to gain.

BMR equations are population estimates with individual error of about 10-15%. They are useful for planning purposes but should not replace a dietitian's assessment for medical weight management. This calculator is for informational purposes only and does not constitute medical advice - consult a qualified healthcare provider before making any health-related decisions.