What is the BMR Calculator?
Your basal metabolic rate is the number of calories your body needs at complete rest to keep you alive: breathing, circulation and cell repair. It is the starting point for any calorie plan.
How to use the BMR tool
- Enter Sex, Age, Weight and Height.
- The result updates instantly as you type, or press Calculate.
- Use Try an example to see how it works, and Reset to start again.
Formula
Mifflin-St Jeor: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5 for men or − 161 for women.
Worked example
With sex Male, age 30 years, weight 70 kg, height 175 cm, the basal metabolic rate comes to 1,649 kcal/day.
Frequently asked questions
What is the difference between BMR and TDEE?
BMR is calories at rest. TDEE adds the calories you burn through daily activity and exercise.
How accurate is this formula?
Mifflin-St Jeor is considered one of the most reliable estimates, but individual metabolism can differ by around 10%.
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Checked by Calcovate · Formula tested against worked examples · Updated 7 Nov 2026 · How we check our calculators. General information only, not financial or medical advice.