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What this calculator does
Estimate calories your body uses at rest using the Mifflin–St Jeor equation.
How to use this calculator
- Enter sex, age, weight, and height.
- Review the calculation assumptions before using the result.
- BMR is a baseline before activity is added.
How to calculate
Enter weight, height, age, and biological sex for the Mifflin–St Jeor estimate.
Worked example
A 30-year-old male at 70 kg and 175 cm has an estimated BMR of 1,649 calories per day.
Understanding your result
BMR is a baseline before activity is added.
- It is an estimate, not a personal nutrition prescription.
- Double-check values and units before calculating.
BMR is an estimate, not medical advice.
Frequently asked questions
What does this bmr calculator do?
Estimate calories your body uses at rest using the Mifflin–St Jeor equation.
How do I use this bmr calculator?
Enter sex, age, weight, and height.
What does the result mean?
BMR is a baseline before activity is added.
What should I check before relying on it?
It is an estimate, not a personal nutrition prescription.
Why does BMR differ between men and women at the same weight and height?
The Mifflin–St Jeor formula includes a fixed adjustment for biological sex, reflecting typical differences in body composition and metabolic rate between men and women at similar size.
Is BMR the number of calories I should eat?
No — BMR is the estimated energy your body uses at complete rest, before any activity is added. For a daily calorie target, use the calorie-needs or TDEE calculator, which multiplies BMR by an activity factor.