How BMR Calculator Works
This tool uses the Mifflin-St Jeor equation, generally considered one of the most accurate BMR formulas for the general population. Men: 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5. Women: 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161. Multiplying BMR by an activity factor estimates your Total Daily Energy Expenditure (TDEE) — the calories you burn including movement and exercise.
How to Use This Tool
- Select your sex, then enter your age, weight and height.
- Choose the activity level that best matches your typical week.
- Select Calculate BMR to see your resting calorie burn and estimated daily needs.
Example
A 30-year-old male weighing 70 kg at 175 cm has a BMR of 10×70 + 6.25×175 − 5×30 + 5 = 1,648.75 calories/day. With moderate exercise (×1.55), his estimated daily needs are about 2,556 calories.
Helpful Tips
- BMR is the energy you'd burn lying still all day — TDEE (the activity-adjusted figure) is the more useful number for planning daily calorie intake.
- To lose weight, most people target a modest deficit below their TDEE rather than below their BMR.
- Re-calculate periodically as your weight changes, since BMR shifts along with it.
Frequently Asked Questions
What's the difference between BMR and TDEE?
BMR is the calories your body needs at complete rest just to function. TDEE adds in the calories burned through daily activity and exercise, using the activity multiplier you select.
Why does the formula differ for men and women?
Men typically carry more lean muscle mass relative to body weight, which burns more calories at rest, so the Mifflin-St Jeor equation subtracts less for men than for women.
Is this accurate for everyone?
It's a well-validated estimate for most adults, but individual metabolism varies. It's less accurate for people with very high muscle mass, pregnancy, or certain medical conditions.
Should I eat exactly at my TDEE?
Eating at your TDEE is intended to maintain your current weight. Eat below it for weight loss or above it for weight gain, adjusted to your goals.
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