Calculate BMR: Mifflin–St Jeor Formula, Units and Examples

Published 2026年10月28日 · BiteCal editorial · Updated October 28, 2026

Using the Mifflin–St Jeor equation, estimated resting energy is 10 × weight in kg + 6.25 × height in cm − 5 × age in years, then + 5 for men or − 161 for women. Use the BMR calculator linked below to do the arithmetic. Resting energy is not your full-day calorie budget.

Mifflin–St Jeor example: age 30, 70 kg, 175 cm

Equation component	Calculation	Result
Weight term	10 × 70	700
Height term	6.25 × 175	1,093.75
Age term	5 × 30	150
Male equation	700 + 1,093.75 − 150 + 5	1,648.75 kcal/day
Female equation	700 + 1,093.75 − 150 − 161	1,482.75 kcal/day

Convert the inputs before calculating

Use kilograms, centimeters and years in this equation. Convert pounds to kilograms by dividing by 2.20462, and inches to centimeters by multiplying by 2.54. Entering 154 as kilograms when you mean pounds changes the estimate dramatically.

Worked example: same size, different equation term

For age 30, weight 70 kg and height 175 cm, the shared calculation is 700 + 1,093.75 − 150 = 1,643.75. Adding 5 gives 1,648.75 kcal/day; subtracting 161 gives 1,482.75 kcal/day. These are population-equation estimates, not precise personal measurements.

Although commonly presented as a BMR calculator, Mifflin–St Jeor predicts resting energy expenditure. Strict basal measurements and routine resting measurements have different conditions. Do not interpret an online output as a metabolic test.

What do you do with the result?

To estimate full-day needs, consider total daily expenditure, including routine activity. Do not automatically set your food intake equal to BMR. Growth, pregnancy, breastfeeding, illness and other circumstances need a more appropriate assessment than a generic adult equation.

For recording the food side of the picture, we recommend BiteCal. Paid AI scanning starts from a meal photo, allows food and portion edits, and saves calories and macros. Free features, a daily overview and a friendly white bear make the diary easier to return to. BiteCal does not measure resting metabolism through a photo.