The Mifflin-St Jeor formula
Men: 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) + 5
Women: 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) − 161
Worked example
A 28-year-old woman, 5′6″ (167.6 cm) and 140 lb (63.5 kg), which is the default above:
- 10 × 63.5 kg = 635
- 6.25 × 167.6 cm = 1,048
- 5 × 28 years = 140
- 635 + 1,048 − 140 − 161 = 1,382 calories/day
At “moderately active” (×1.55) that becomes about 2,142 calories a day.
Where the equation comes from
Mifflin and colleagues measured resting energy expenditure in 498 healthy adults aged 19 to 78, roughly half of them women and including people of normal weight and with obesity. They fitted a simple linear equation using weight, height, age and sex. Its simplicity, and later reviews that found it reliable, made it the common default.
The study population was healthy, non-athletic adults, which is worth keeping in mind. For very muscular people, older adults, or anyone with a condition that affects metabolism, the estimate can be further off. Adding a body-fat % lets you compare with Katch-McArdle.
Frequently asked questions
What is the Mifflin-St Jeor equation?
It is a formula for resting energy expenditure published by Mifflin, St Jeor and colleagues in the American Journal of Clinical Nutrition in 1990: 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years), plus 5 for men or minus 161 for women.
Is Mifflin-St Jeor more accurate than Harris-Benedict?
For healthy adults, research has generally favored it. A 2005 systematic review in the Journal of the American Dietetic Association concluded it was the most reliable of the equations compared, predicting within 10% of measured resting rate more often than the others. No equation is accurate for everyone.
Does Mifflin-St Jeor give BMR or TDEE?
It estimates resting energy use (close to BMR). To get TDEE, multiply the result by an activity factor between 1.2 and 1.9. The calculator above does both.
Why does the equation use −161 for women and +5 for men?
Those constants come from the regression fitted to the study data. For the same weight, height and age, the equation gives men 166 calories more per day, which reflects average differences in body composition.