Your BMR (Basal Metabolic Rate) is the number of calories your body burns in 24 hours at complete rest — just to keep your heart beating, lungs breathing and temperature steady. It is the foundation every calorie target is built on. Enter your details below to find your BMR and what it means at every activity level.
BMR Calculator
Estimated daily calories at each activity level (BMR × activity multiplier):
| Activity level | Calories (kcal/day) |
|---|
Estimate only — not medical advice.
How the BMR Calculator Works
This calculator uses the Mifflin-St Jeor equation, which research has found to be the most accurate BMR formula for most adults:
- Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
The table under your result shows your estimated daily calorie needs at five activity levels (BMR × 1.2 to × 1.9). That maintenance number is also known as your TDEE.
Worked Example
A 30-year-old man, 80 kg, 178 cm: BMR = (10 × 80) + (6.25 × 178) − (5 × 30) + 5 = 1,768 kcal/day. At a moderate activity level (× 1.55) he maintains his weight on about 2,740 kcal/day.
BMR vs TDEE — What Is the Difference?
BMR is what you burn doing absolutely nothing. TDEE (Total Daily Energy Expenditure) is BMR plus all your movement — work, walking, training. Never plan your diet below your BMR for long periods: eating under it usually means your body is not getting enough for basic functions.
Frequently Asked Questions
What is a good BMR?
There is no single “good” number — BMR depends on your size, age and sex. Most adults fall between roughly 1,200 and 2,000 kcal/day. A higher BMR usually just means a bigger body or more muscle, not better health.
Can I increase my BMR?
Yes, modestly. Muscle tissue burns more at rest than fat, so gaining muscle raises your BMR a little. Crash diets do the opposite — they lower it. Use the TDEE Calculator to set a sensible target instead.
Should I eat at my BMR to lose weight?
Eating exactly at BMR means a large deficit for most active people, which is hard to sustain and can cost muscle. A smaller deficit below your TDEE (about 20%) is the safer standard approach.
How accurate is the Mifflin-St Jeor equation?
Within roughly ±10% for most adults. It cannot account for muscle mass precisely — if you are very muscular, your true BMR may be slightly higher.