BMR Calculator
Estimate how much energy your body uses at rest. Your basal metabolic rate is the starting point for daily calorie estimates; the table shows how activity changes it.
Published by Reeve Editorial Team · Methods and sources updated
Basal metabolic rate (BMR)
1,452 kcal/day
Estimated energy used at complete rest, before any activity.
| Usual activity | Factor | Daily energy |
|---|---|---|
| Mostly sedentary | ×1.2 | 1,742 kcal |
| Light activity | ×1.375 | 1,997 kcal |
| Moderate activity | ×1.55 | 2,251 kcal |
| High activity | ×1.725 | 2,505 kcal |
| Very high activity / physical work | ×1.9 | 2,759 kcal |
Daily energy multiplies BMR by an activity factor. The TDEE calculator uses the same equation and lets you choose your level.
Inputs stay in this tab. Saving keeps a copy on this device until you reset or clear it.
Adult educational estimates. Pregnancy, breastfeeding, medical conditions, and eating-disorder recovery need individualized guidance. No calorie number here establishes nutritional adequacy.
How this tool works
BMR is estimated with the Mifflin–St Jeor equation: 10 × weight (kg) + 6.25 × height (cm) − 5 × age (years), then + 5 for the male equation or − 161 for the female equation.
Strictly, the equation predicts resting metabolic rate (RMR), which is measured under slightly less strict conditions than BMR. The two values are close and are often used interchangeably. Daily energy (TDEE) multiplies the result by a broad activity factor.
A systematic review found Mifflin–St Jeor predicted resting metabolic rate within 10% of measured values in more healthy adults than the other equations it compared, but individual errors can still be substantial. Treat the result as an estimate, not a measurement.
Sources
Frequently asked questions
What is the difference between BMR and TDEE?
BMR estimates the energy you use at rest. TDEE (total daily energy expenditure) adds the energy used for movement, exercise, and digesting food. This tool shows both; the TDEE calculator uses the same equation with your chosen activity level.
Should I eat less than my BMR to lose weight?
BMR is an estimate of resting energy, not a recommended intake. Weight-loss targets are usually set from estimated daily energy (TDEE) rather than BMR. Very low intakes need individual professional guidance.
Is BMR the same as RMR?
Not exactly. BMR is measured under stricter conditions than resting metabolic rate (RMR), so RMR is usually slightly higher. Predictive equations like Mifflin–St Jeor estimate RMR, and the terms are often used interchangeably.
Why does the equation ask for a sex category?
The published Mifflin–St Jeor equations use different constants for male and female groups. Choose the equation that is most appropriate for you, and treat the result as an estimate rather than an identity statement or medical measurement.