How bmr calculator works
Your Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest just to keep you alive — powering breathing, circulation, cell production, and temperature regulation. It is the largest single component of your daily energy expenditure, typically 60 to 70 percent of the calories you use each day.
This calculator uses the Mifflin-St Jeor equation by default, the formula most dietitians now recommend. For men it is 10 times weight (kg) plus 6.25 times height (cm) minus 5 times age (years) plus 5. For women the constant is -161 instead of +5. You can also switch to the older Harris-Benedict equation, which gives slightly higher estimates.
Enter your gender, age, weight in kilograms, and height in centimetres, then choose a formula. The result is your daily calorie floor at rest. To estimate your actual maintenance calories, multiply BMR by an activity factor — try the related Calorie Calculator for that. BMR is an estimate, not a measurement; treat it as a starting point.
Frequently asked questions
What is a good BMR?
A typical adult BMR ranges from about 1,400 to 1,800 kcal/day for women and 1,600 to 2,000 kcal/day for men. BMR depends mostly on weight, height, age, and gender — there is no single "good" number, only what is normal for your body.
Mifflin-St Jeor or Harris-Benedict — which is better?
Mifflin-St Jeor is the modern standard and tends to be more accurate for most people. Harris-Benedict is older and usually estimates a few percent higher. This calculator defaults to Mifflin-St Jeor and lets you compare both.
Does muscle change my BMR?
Yes. Lean muscle mass burns more calories than fat even at rest, so more muscular people have a higher BMR. The standard formulas estimate this indirectly through weight and gender but do not measure body composition directly.
How is BMR different from TDEE?
BMR is calories burned at complete rest. TDEE (total daily energy expenditure) multiplies BMR by an activity factor to account for movement and digestion. Use the Calorie Calculator to estimate your TDEE and goal calories.
