BMR Calculator — Calculate Your Basal Metabolic Rate
Use this free BMR calculator to find out how many calories your body burns at rest. Enter your age, gender, weight and height to get your Basal Metabolic Rate, your TDEE at every activity level and a full calorie breakdown for weight loss, maintenance and weight gain goals.
BMR Calculator
Try Another Calculator
What Is BMR?
Basal Metabolic Rate is the number of calories your body needs to maintain basic life functions at complete rest — breathing, blood circulation, temperature regulation and cell production. It represents the minimum calories your body needs to survive even if you stayed in bed all day.
BMR accounts for roughly 60-75% of your total daily calorie burn. The rest comes from physical activity and digesting food.
BMR vs TDEE — What's the Difference?
BMR is your calorie burn at complete rest — no movement, no exercise, no digestion.
TDEE (Total Daily Energy Expenditure) is your BMR multiplied by your activity level. It’s the total calories you actually burn in a typical day including all movement, exercise and daily activity.
TDEE is the number you use for setting calorie targets. Eat below your TDEE to lose weight, above it to gain weight, and at it to maintain your current weight.
The Mifflin-St Jeor Formula
This calculator uses the Mifflin-St Jeor equation, widely considered the most accurate BMR formula for most people:
Men: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
Women: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
The result shows below the calculator with your exact numbers plugged in so you can see exactly how it was calculated.
What Affects Your BMR?
Body size — larger people have higher BMRs as they have more tissue to maintain.
Muscle mass — muscle burns more calories at rest than fat. More muscle means a higher BMR.
Age — BMR decreases with age, typically by about 2% per decade after 20.
Gender — men generally have higher BMRs than women due to greater muscle mass.
Genetics — some people naturally have faster or slower metabolisms.
What is a normal BMR?
For most adults BMR ranges from 1,400 to 1,800 calories per day. Men typically have higher BMRs than women due to greater average muscle mass. Use the calculator above for your specific result.
What is the difference between BMR and TDEE?
BMR is calories burned at complete rest. TDEE is BMR multiplied by your activity level — the total calories you actually burn in a day. TDEE is what you use to set calorie targets for weight loss or gain.
How accurate is this calculator?
The Mifflin-St Jeor equation is the most validated formula for estimating BMR and is used by most nutrition professionals. Individual results vary based on muscle mass, genetics and hormone levels. Use it as a starting point and adjust based on real results over 2-3 weeks.
Does BMR change with age?
Yes — BMR typically decreases by around 2% per decade after age 20. This is mainly due to gradual loss of muscle mass with age. Resistance training can help maintain muscle and slow this decline.
Can I increase my BMR?
Yes — building muscle through resistance training is the most effective way to increase BMR since muscle burns more calories at rest than fat. Adequate protein intake and avoiding very low calorie diets also helps preserve BMR.
Is this calculator free?
Yes completely free with no sign-up needed.