How to Use This BMR Calculator
Enter your age, gender, weight, and height. The calculator uses the Mifflin-St Jeor equation, widely regarded as the most accurate BMR formula for the general population.
The Mifflin-St Jeor Equation
Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
This formula was published in 1990 and is endorsed by the Academy of Nutrition and Dietetics as the most reliable estimation method.
Understanding Your Results
Your BMR represents the minimum calories your body needs to function at rest. For actual daily calorie needs, multiply by an activity factor (see our TDEE Calculator for details).
Frequently Asked Questions
❓ What is BMR?
BMR (Basal Metabolic Rate) is the number of calories your body burns at rest to maintain basic life-sustaining functions like breathing, circulation, and cell production. It accounts for 60-75% of your total daily calorie expenditure.
❓ How is BMR calculated?
The most widely used formula is the Mifflin-St Jeor equation. For men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5. For women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161.
❓ What is a normal BMR?
Average BMR ranges from about 1,200 to 2,000+ calories per day depending on body size, age, and sex. Larger, younger people generally have higher BMR.
❓ Can I eat below my BMR to lose weight?
Eating below your BMR for extended periods can slow your metabolism, cause muscle loss, and lead to nutrient deficiencies. Most health professionals recommend eating at or slightly above your BMR while using exercise to create a calorie deficit.
❓ Does BMR decrease with age?
Yes, BMR naturally decreases about 1-2% per decade after age 20, primarily due to loss of muscle mass. This can be partially offset through regular strength training.
❓ How can I increase my BMR?
Building muscle through strength training is the most effective way to increase BMR, as muscle burns more calories at rest than fat. Adequate protein, hydration, and sleep also help.
❓ Is the Mifflin-St Jeor formula accurate?
It's considered the most accurate BMR formula for most people. Developed in 1990, it's endorsed by the Academy of Nutrition and Dietetics. Individual variations exist.
❓ What's the difference between BMR and TDEE?
BMR is calories burned at complete rest. TDEE (Total Daily Energy Expenditure) includes BMR plus calories burned through daily activities and exercise, typically 1.2–1.9× your BMR.