Calculate calories your body needs at complete rest before adding activity.
Basal metabolic rate (BMR) estimates the calories required for basic life-sustaining functions such as breathing, circulation, and cellular activity.
BMR is the base of calorie planning. Total daily energy expenditure is then estimated by multiplying BMR by an activity factor.
Mifflin-St Jeor uses a different constant for men and women.
Use completed years.
Provide body weight in kg (or convert from lb).
Provide body height in cm (or convert from ft/in).
Apply the equation and read kcal/day output.
Pair with activity multiplier to estimate maintenance calories.
Men: BMR = 10W + 6.25H - 5A + 5; Women: BMR = 10W + 6.25H - 5A - 161
The Mifflin-St Jeor model estimates resting metabolism from weight (W), height (H), and age (A), with sex-specific constants.
BMR = 10(80) + 6.25(180) - 5(30) + 5 = 1780 kcal/day
Estimated BMR: 1,780 kcal/day
BMR = 10(62) + 6.25(165) - 5(28) - 161 = 1350.25
Estimated BMR: 1,350 kcal/day
TDEE = 1,780 x 1.55 = 2,759
Estimated maintenance: ~2,760 kcal/day