BMR calculator
Your basal metabolic rate is the calories your body burns just to stay alive at rest. It's the foundation of every calorie target, start here, then layer your activity on top.
BMR calculation example
For a 30-year-old man who weighs 75 kg and is 175 cm tall, the Mifflin-St Jeor calculation is 10 × 75 + 6.25 × 175 − 5 × 30 + 5. That equals 750 + 1,093.75 − 150 + 5 = 1,699 kcal/day after rounding.
This result estimates energy used at rest; it is not the example person's maintenance intake because it excludes routine movement and exercise. The formula assumes population-average relationships among age, sex, height, and weight, so body composition and individual variation can make measured energy use different. Apply an activity multiplier with the TDEE calculator before choosing an intake target, or use the calorie deficit calculator for a goal-based estimate.
What BMR means
Basal metabolic rate is the energy your body uses at complete rest to keep you alive, breathing, pumping blood, maintaining temperature, and repairing cells. For most people it's 60–70% of all the calories they burn in a day, which is why it's the starting point for any nutrition plan.
The equation we use
This calculator uses the Mifflin-St Jeor equation, which studies generally find more accurate than the older Harris-Benedict formula:
- Men: 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
- Women: 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
It's an estimate based on population averages, your real BMR depends on muscle mass, genetics, and hormones, but it's reliably close enough to plan around.
BMR vs. TDEE
BMR is only the at-rest piece. Once you account for moving and exercising, you get your total daily energy expenditure (TDEE), which is the number to actually eat at. To lose weight, take your TDEE and subtract a deficit with the calorie deficit calculator, don't try to eat at your BMR alone.
Frequently asked questions
What is BMR?
Your basal metabolic rate, the calories your body burns at complete rest to keep essential functions running. It's the largest single piece of your daily calorie burn.
What equation does this BMR calculator use?
The Mifflin-St Jeor equation: 10 × weight(kg) + 6.25 × height(cm) − 5 × age, then +5 for men or −161 for women. It's generally more accurate than the older Harris-Benedict formula.
Should I eat my BMR to lose weight?
No. You also burn calories moving and exercising, so eating only your BMR usually makes the deficit too aggressive. Use your TDEE as the baseline and subtract a moderate deficit from there.
More free tools
From numbers to a habit that sticks.
Knowing your BMR is step one. Wisely makes the daily part effortless, snap a photo, get honest calories and macros, and let Sage keep you on track. Join the waitlist for launch day.