BMR Calculator
How it works
We calculate BMR with the Mifflin-St Jeor equation, the most accurate of the common formulas: 9.99 × weight(kg) + 6.25 × height(cm) − 4.92 × age, plus 5 for men or minus 161 for women.
Maintenance calories (your TDEE) = BMR × an activity multiplier from 1.2 (sedentary) to 1.9 (extra active). Eat around this number to hold your weight, below it to lose, above it to gain.
Frequently asked questions
What is basal metabolic rate (BMR)?+
Your BMR is the number of calories your body burns at complete rest just to keep you alive — breathing, circulation, cell repair. It's the single biggest part of your daily calorie burn.
What's the difference between BMR and maintenance calories (TDEE)?+
BMR is your at-rest burn. Maintenance calories (TDEE, total daily energy expenditure) is your BMR multiplied by an activity factor from 1.2 to 1.9. TDEE is what you actually burn on a normal day, so it's the number to eat around to hold your weight.
Which BMR formula is most accurate?+
This calculator uses the Mifflin-St Jeor equation, which research finds more accurate for most people than the older Harris-Benedict formula. It estimates within about 10% for the average person, though very muscular or very lean bodies can differ.
How many calories should I eat to lose weight?+
Eat below your maintenance calories. A deficit of about 500 calories a day is a common, sustainable rate that loses roughly 0.5 kg (1 lb) a week. Don't drop below about 1,200 (women) or 1,500 (men) calories a day without medical guidance.
Does BMR change with age?+
Yes. BMR falls gradually with age as muscle mass declines, which is why the formula subtracts calories for each year. Keeping muscle through resistance training helps offset the drop.