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v2.90.2

Basal Metabolic Rate Calculator

How much energy does your body use at rest? This calculator, often called a basal metabolic rate calculator, estimates resting expenditure with a published equation.

Units

Formula sex

The published equations use two coefficients based on the sex studied. No coefficient determines your body composition; it is always an estimate.

Free, no account: nothing is saved or sent.

Estimated resting energy expenditure

Complete to see your result

  • Weight
  • Height
  • Age
  • Sex
  • Confirmation

Enter your weight, height, age, and activity factor, then confirm the calculation setting. Ranges: 20 to 350 kg, 100 to 250 cm, 19 to 78 years.

Understand the calculation

Mifflin-St Jeor estimates resting energy expenditure from weight, height, age, and the study’s sex coefficient. The study population was ages 19 to 78. Actual needs may differ from this calculation.

Resting (kcal/day) = 10 × weight (kg) + 6.25 × height (cm) - 5 × age (years) + coefficient: +5 male or -161 female.

Fictional calculation example

For a fictional 35-year-old adult weighing 75 kg and measuring 175 cm, using the male coefficient: 750 + 1,093.75 - 175 + 5 = 1,673.75 kcal/day at rest. The tool displays approximately 1,670 kcal/day after rounding.

Scientific 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.

Your questions

Are basal metabolism and resting expenditure the same thing?
They are similar concepts, but measurement conditions differ. The equation used estimates resting expenditure; it does not measure your basal metabolism under experimental conditions.

Does this result correspond to how many calories to eat?
No. Daily expenditure also includes digestion and activity throughout the day. Resting expenditure is neither a calorie target nor a threshold to reach for weight loss.

Is the formula accurate for everyone?
No. It is an estimate derived from a studied population, not an individual measurement. Body composition, health, and other factors can change the result. The tool does not apply this equation to children or during pregnancy or breastfeeding.
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