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BMR Calculator
Find your basal metabolic rate — the calories your body burns at complete rest — with the Mifflin-St Jeor equation. Enter your details for an instant estimate, metric or imperial.
Why BMR matters
BMR is the foundation of every calorie target. It’s the energy you’d burn lying in bed all day. Multiply it by how active you are and you get your real daily burn (TDEE); eat below that and you lose, above it and you gain. Knowing the number is step one — the results come from what you eat against it.
Questions
- What is BMR?
- Basal metabolic rate is the energy your body uses at complete rest just to keep you alive — breathing, circulation, cell repair. It’s the biggest chunk of your daily calorie burn, before any movement is added.
- BMR vs TDEE — what’s the difference?
- BMR is rest-only. TDEE (total daily energy expenditure) is your BMR multiplied by an activity factor, so it includes movement and exercise. To set a weight goal you use TDEE — try our TDEE & Calorie Calculator next.
- Which formula does this use?
- Mifflin-St Jeor, the equation most recommended for the general population today. For men: 10×kg + 6.25×cm − 5×age + 5; for women the last term is −161.
- How accurate is it?
- It’s an estimate from a population formula — typically within about 10% for most people. Body composition, genetics, and hormones shift your true resting burn, so use it as a starting point and adjust based on real results.
This calculator gives a general fitness estimate, not medical advice. If you have a medical condition or any history of disordered eating, please talk to a doctor or qualified professional.