Calculate your Basal Metabolic Rate
Find out exactly how many calories your body burns at rest — the foundation of every calorie target, weight loss plan, and fitness goal.
What is BMR?
BMR — Basal Metabolic Rate — is the number of calories your body burns over 24 hours at complete rest: breathing, circulating blood, regulating body temperature, and keeping organs functioning. It does not include any calories from movement or exercise.
For most adults, BMR accounts for 60–75% of total daily calorie burn — the single largest component of energy expenditure. Even on a completely inactive day, most of the calories you burn come from resting metabolism, not activity.
How to use your result
Your BMR is not a daily calorie target — it is your resting baseline. Multiply it by your activity level to get your TDEE (Total Daily Energy Expenditure) — the actual calories your body burns on a typical day.
- Lose weight: eat 300–500 kcal below TDEE — roughly 0.5 kg fat loss per week
- Maintain weight: eat at TDEE
- Gain weight: eat 300–500 kcal above TDEE
Use our TDEE calculator or calorie deficit calculator to set your exact daily target.
Activity level multipliers
| Activity level | Description | Multiplier |
|---|---|---|
| Sedentary | Desk job, little or no exercise | × 1.2 |
| Lightly active | Light exercise 1–3 days/week | × 1.375 |
| Moderately active | Moderate exercise 3–5 days/week | × 1.55 |
| Very active | Hard exercise 6–7 days/week | × 1.725 |
| Extremely active | Physical job + daily training | × 1.9 |
BMR vs TDEE
| Metric | What it measures | Use it for |
|---|---|---|
| BMR | Calories at complete rest | Your metabolic baseline |
| TDEE | Total daily calorie burn | Setting your daily intake target |
TDEE is always 1.2–1.9× higher than BMR depending on activity. Never set your intake at or below BMR — doing so causes muscle loss and metabolic slowdown.
Frequently asked questions
What is BMR and why does it matter?
BMR is the minimum calories your body needs at complete rest to keep organs functioning. It sets the floor for every calorie calculation — eating consistently below it causes muscle loss and metabolic adaptation over time.
Should I eat at my BMR to lose weight?
No. BMR is a resting baseline, not a daily target. Calculate TDEE first (BMR × activity multiplier), then eat 300–500 kcal below that. Eating at BMR ignores all the calories burned through movement and digestion.
How accurate is this calculator?
The Mifflin-St Jeor equation used here is accurate to within ±10% for most healthy adults — the most validated non-lab formula for the general population. Track your actual weight change over 2–4 weeks and adjust your target if results differ.
How often should I recalculate?
Recalculate whenever your weight changes by 5 kg or more, or when your exercise habits change significantly. BMR decreases as you lose weight — if you never recalculate, your deficit shrinks and progress stalls.
How can I raise my BMR?
Build muscle through resistance training — muscle burns more calories at rest than fat. Adequate sleep and sufficient protein intake also support a healthy resting metabolic rate over time.
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