BMR calculator: estimate basal metabolic rate and TDEE
Calculate the calories your body is estimated to use at rest, then compare total daily energy expenditure across five activity levels. Choose pounds, feet and inches or kilograms and centimeters.
Calculate your basal metabolic rate (BMR)
What BMR means
Basal metabolic rate is the energy your body is estimated to use at complete rest for essential functions. It covers processes such as breathing, circulation, cellular activity and temperature regulation. It does not include walking, work, exercise or digestion.
BMR is a useful starting point, but it is not a recommended calorie intake. Total daily energy expenditure is the more relevant estimate for everyday planning.
Mifflin-St Jeor BMR formula
The equation uses weight in kilograms (W), height in centimeters (H) and age in years (A). US-unit inputs are converted before calculation.
| Equation input | Formula |
|---|---|
| Male | 10W + 6.25H − 5A + 5 |
| Female | 10W + 6.25H − 5A − 161 |
BMR vs TDEE
TDEE estimates energy used across an ordinary day. The calculator multiplies BMR by an activity factor, but short labels cannot capture every job, training schedule or movement pattern. Treat the values as a range to test against real weight and intake trends.
| Activity level | Multiplier |
|---|---|
| Sedentary | 1.20 |
| Light activity | 1.375 |
| Moderate activity | 1.55 |
| Very active | 1.725 |
| Extra active | 1.90 |
Why your actual energy use may differ
Equations estimate the average relationship between age, height, weight and resting energy use. They do not directly measure muscle mass, hormones, illness, medication, pregnancy, adaptive changes or spontaneous daily movement.
- Use the result as a starting range, not an exact daily allowance.
- Compare the estimate with several weeks of consistent intake and weight data.
- Recalculate after a meaningful change in body weight or activity.
- Seek individualized advice when health conditions, pregnancy or eating-disorder risk affect energy planning.
Sources
Nutrition values are estimates based on authoritative food-composition data and public-health guidance. Product labels and serving sizes vary.
- Mifflin-St Jeor resting energy equation
Original peer-reviewed study describing the equation used by this calculator.
- NIDDK Body Weight Planner
US National Institute of Diabetes and Digestive and Kidney Diseases tool and guidance for weight and energy planning.
- Dietary Guidelines for Americans
US government evidence-based guidance on energy balance and healthy dietary patterns.
Frequently asked questions
- What is BMR?
- Basal metabolic rate is the estimated energy your body uses at complete rest to maintain essential functions such as breathing, circulation and temperature regulation.
- What is the difference between BMR and TDEE?
- BMR estimates resting energy use. TDEE estimates total daily energy expenditure by multiplying BMR by an activity factor.
- How accurate is a BMR calculator?
- It gives a population-based estimate, not a measurement. Body composition, health, medication, environment and actual activity can make individual energy use higher or lower.
- Should I eat fewer calories than my BMR?
- BMR is not a calorie target. Weight planning should start from estimated total daily expenditure and account for health, nutrition adequacy and a sustainable rate of change.
- Does the calculator support pounds and feet?
- Yes. Choose US units for pounds, feet and inches, or metric for kilograms and centimeters. The calculator converts inputs before applying the same equation.