Free BMR Calculator
Work out your Basal Metabolic Rate — the calories your body burns at complete rest — no signup, nothing sent to a server.
BMR
—
calories/day at complete rest
How to calculate BMR
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1
Choose your unit system
Pick Metric (cm/kg) or Imperial (ft-in/lb).
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2
Enter sex, age, height, and weight
Fill in each field — the result updates instantly as you type.
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3
Read your BMR
Your estimated resting calorie burn appears below, in calories per day.
Example use cases
Weight loss or gain planning
Use BMR as the baseline before adding activity level to plan a calorie deficit or surplus.
Nutrition & diet tracking
Understand your resting energy needs before setting a daily calorie target.
Fitness program design
Estimate resting energy expenditure as part of a broader training and nutrition plan.
Frequently asked questions
How is BMR calculated here?
This calculator uses the Mifflin-St Jeor equation, widely considered one of the most accurate BMR formulas for the general population: for men, BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5; for women, subtract 161 instead of adding 5.
What is BMR used for?
BMR is the number of calories your body needs just to maintain basic functions like breathing and circulation while at complete rest. It's the starting point for working out total daily calorie needs — see the Calorie Calculator to add activity level.
Why does BMR differ by sex?
On average, men tend to have more lean muscle mass relative to body weight than women, which raises resting energy expenditure — the formula accounts for this with a fixed offset.
Is my data sent to a server?
No. The calculation runs entirely in your browser — nothing is transmitted or logged.