BMR Calculator — Mifflin-St Jeor vs Harris-Benedict
CalculatorA BMR calculator estimates the minimum daily energy your body needs at complete rest, using both the Mifflin-St Jeor and Harris-Benedict equations for comparison.
What is it
Basal metabolic rate (BMR) is the daily energy used only for vital functions such as breathing, body temperature, and heartbeat. This tool computes the 1990 Mifflin-St Jeor equation (recommended by validation studies) alongside the 1984 revised Harris-Benedict equation and shows the difference. Both are statistical formulas for average adults, so results can differ from measured values by 10% or more with high or low muscle mass, and they do not replace medical diagnosis or prescriptions.
How to use
- 1Enter the sex code (male 1, female 0).
- 2Enter age, height (cm), and weight (kg).
- 3Press calculate to compare BMR from both equations.
Reference
| Equation | Male | Female |
|---|---|---|
| Mifflin-St Jeor (1990) | 10W + 6.25H − 5A + 5 | 10W + 6.25H − 5A − 161 |
| Revised Harris-Benedict (1984) | 88.362 + 13.397W + 4.799H − 5.677A | 447.593 + 9.247W + 3.098H − 4.330A |
Sources & standards
- A new predictive equation for resting energy expenditure in healthy individuals (Mifflin-St Jeor, 1990) - The American Journal of Clinical Nutrition
- The Harris Benedict equation reevaluated (Roza & Shizgal, 1984) - The American Journal of Clinical Nutrition
FAQ
What is the BMR of a 30-year-old male, 175 cm and 75 kg?
About 1,699 kcal by Mifflin-St Jeor and about 1,763 kcal by the revised Harris-Benedict equation. The two statistical models differ slightly.
Which BMR equation should I use?
Mifflin-St Jeor is recommended: validation studies found it has the smallest average error against measured values, while Harris-Benedict tends to overestimate. Both are shown for comparison.
Is my body data sent to a server?
No. This calculator runs entirely in your browser and does not send or store your inputs.