Skip to content
Hakeemly
ع

BMR Calculator

Basal metabolic rate by the Mifflin–St Jeor equation.

For everyoneWeight & body compositionv1.0.1

Your measurements

Sex
years

Calculated on your device. Nothing is sent to a server.

Your result will appear here

Enter your measurements, then press Calculate.

Methodology

Mifflin–St Jeor (1990)

Men: 10W + 6.25H − 5A + 5; Women: 10W + 6.25H − 5A − 161 (W kg, H cm, A years)

Estimates the energy your body uses at complete rest. The equation predicts resting energy expenditure, commonly used as an estimate of BMR. Reviews by the Academy of Nutrition and Dietetics found it the most accurate of the common equations for healthy adults.

Who it is for
Healthy adults aged 18 and over; not in pregnancy.
Version
1.0.1

How this calculator works

Where the formula comes from

  • Mifflin, St Jeor and colleagues (1990) derived the equation from 498 healthy adults aged 19–78 (251 men, 247 women; 264 normal-weight and 234 obese), with resting energy expenditure measured by indirect calorimetry.[1]
  • The full regression explained 71% of the variation (R² = 0.71); simplified sex-specific versions did not reduce its predictive value.[1]

The inputs

  • Men: 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years) + 5; women: the same − 161, in kcal/day.[1]
  • The equation predicts resting energy expenditure, which is commonly used as an estimate of basal metabolic rate.[1]

Versions and alternatives

  • Older equations include Harris–Benedict (which overestimated measured values by about 5% in the 1990 study), Owen and WHO/FAO/UNU.[1][2]

Where accuracy falls (published evidence)

  • A 2005 systematic review found Mifflin–St Jeor predicted resting metabolic rate within 10% of the measured value in more non-obese and obese adults than other equations, but noteworthy individual errors remain.[2]
  • Older adults and US ethnic minorities were under-represented in the studies that developed and validated these equations.[2]

Sources

  1. Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241–247. doi:10.1093/ajcn/51.2.241
  2. Frankenfield D, Roth-Yousey L, Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. J Am Diet Assoc. 2005;105(5):775–789. doi:10.1016/j.jada.2005.02.005

Compiled from the published sources above. Every statement was agreed independently by three AI research tools (Claude, ChatGPT, DeepSeek) and its source verified in PubMed or Crossref by the Hakeemly editorial team. Not reviewed by a doctor unless stated. Agreed on

Worked example: how to calculate BMR

Inputs

Sex
Male
Age
30 years
Height
180 cm
Weight
80 kg

Result

Basal metabolic rate
1,780 kcal/day

Calculation:

800 + 1125 − 150 + 5 = 1780

An illustration with sample values, worked out with the same method the tool above uses.

Limitations

  • Individual values can differ by 10% or more.
  • Not valid during pregnancy.
  • Older adults and some ethnic groups were under-represented in the studies behind the equation (Frankenfield 2005).

References

  1. Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241–247. doi:10.1093/ajcn/51.2.241
  2. Frankenfield D, Roth-Yousey L, Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. J Am Diet Assoc. 2005;105(5):775–789. doi:10.1016/j.jada.2005.02.005

Continue with your measurements

Shared measurements carry over automatically, in this tab only.