BMR Calculator
Find the calories your body burns at complete rest using the Mifflin-St Jeor equation.
– kcal/day
This is your Basal Metabolic Rate — the energy you burn at rest. Multiply by your activity level for daily needs:
| Sedentary (little exercise) | – |
|---|---|
| Light (1–3 days/week) | – |
| Moderate (3–5 days/week) | – |
| Active (6–7 days/week) | – |
| Very active (athlete) | – |
What is BMR?
Your Basal Metabolic Rate (BMR) is the number of calories your body needs to keep you alive at complete rest — powering your heart, lungs, brain, and other organs. It accounts for roughly 60–75% of the calories you burn each day, making it the single largest part of your total energy use. Knowing your BMR is the starting point for any weight loss, maintenance, or muscle-gain plan.
How BMR is calculated
This calculator uses the Mifflin-St Jeor equation, which is widely regarded as the most accurate formula for modern populations. For men, BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5. For women, the final figure is −161 instead of +5. Your BMR depends mainly on your sex, age, height, and weight, because muscle and organ mass drive resting energy use.
BMR vs TDEE
BMR is your at-rest calorie burn. Your Total Daily Energy Expenditure (TDEE) adds the calories you burn through daily activity and exercise. To get your TDEE, multiply your BMR by an activity factor — the calculator above shows all five levels for you. For weight loss, eat 300–500 calories below your TDEE; for weight gain, eat 300–500 above it, and never drop below your BMR for sustained periods.
Frequently asked questions
Should I eat below my BMR to lose weight faster?
No. Eating below your BMR can slow your metabolism, cause muscle loss, and is hard to sustain. Create your calorie deficit from your TDEE instead.
How can I increase my BMR?
Building muscle through strength training is the most effective way, since muscle burns more calories at rest than fat. Staying active and eating enough protein also help.
Disclaimer: This calculator provides estimates for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before making health decisions.