How to use this calculator
- Enter your own values in the labeled fields. Check the units and assumptions before comparing results. Only the fields needed for your selected calculation mode are shown.
- Your answer updates automatically. Review the calculation steps to see exactly how it was calculated.
- Copy, share, save, or download your result. Saved inputs stay on this device.
How the calculation works
Although commonly called a BMR calculator, this equation predicts resting energy expenditure from weight in kilograms, height in centimeters, age, and a sex coefficient. Measured basal and resting metabolism are related but not identical. A population equation cannot replace indirect calorimetry or individualized clinical assessment.
A worked example
For a 35-year-old male at 75 kg and 180 cm: 750 + 1,125 − 175 + 5 = 1,705 kcal/day.
Reading your result
Use the main result together with its units and supporting figures. Display values are rounded; calculations keep their underlying precision. A change in inputs or assumptions can change the answer. Compare the step-by-step working with your intended use before relying on an estimate.
Frequently asked questions
Does this include exercise?
No. It estimates resting needs. Use the TDEE calculator for a rough activity-adjusted estimate.
How precise is the estimate?
Individual metabolism can differ substantially from the equation. Treat the result as an estimate.
Sources & methodology
Mifflin et al. (1990), original research ↗
Formula review: October 24, 2026. Read our methodology.