Resting metabolic rate in healthy adults can be estimated within roughly 10% using validated prediction equations (Mifflin-St Jeor, revised Harris-Benedict), provided accurate height, weight, age, and sex inputs are available.

In plain English

Simple formulas can estimate the calories your body burns at rest within about 10 percent for most healthy adults. They are less accurate for people who are very lean or carrying a lot of extra weight.

Why it works

Prediction equations model metabolic rate as a function of fat-free mass (approximated through height, weight, age, and sex). The underlying physiology — mitochondrial ATP production at rest — scales predictably with lean tissue mass.

The evidence

• Karagun, B., Baklaci, N. (2024). Comparative Analysis of Basal Metabolic Rate Measurement Methods in Overweight and Obese Individuals: A Retrospective Study. Medicine.

• Pavlidou, E., Papadopoulou, S.K., Seroglou, K. et al. (2023). Revised Harris-Benedict Equation: New Human Resting Metabolic Rate Equation. Metabolites.

• Flack, K.D., Siders, W.A., Johnson, L. et al. (2016). Cross-Validation of Resting Metabolic Rate Prediction Equations. Journal of the Academy of Nutrition and Dietetics.

• Weijs, P.J. (2008). Validity of Predictive Equations for Resting Energy Expenditure in US and Dutch Overweight and Obese Class I and II Adults Aged 18-65 Y. The American Journal of Clinical Nutrition.

• Mifflin, M.D., St Jeor, S.T., Hill, L.A. et al. (1990). A New Predictive Equation for Resting Energy Expenditure in Healthy Individuals. The American Journal of Clinical Nutrition.

Why we call confidence high

Multiple cross-validation studies confirm Mifflin-St Jeor as the most accurate general-purpose BMR equation, consistently outperforming older formulas in diverse populations.

Where it applies

Healthy adults