BMR Calculator
Calculate your Basal Metabolic Rate and daily calorie needs
What is Basal Metabolic Rate (BMR)?
Basal Metabolic Rate (BMR) is the number of calories your body needs to perform basic life-sustaining functions at rest, such as breathing, circulation, cell production, and nutrient processing. BMR accounts for approximately 60%-75% of your total daily energy expenditure and represents the minimum energy required to keep your body functioning while completely at rest.
How to Use
- Select your gender and calculation formula
- Choose unit system and enter your age, height, and weight (Katch-McArdle formula also requires body fat percentage)
- Click the calculate button to view your BMR result and daily calorie needs for different activity levels
Formula Guide
Comparing the Three Formulas
The Mifflin-St Jeor equation is considered the most accurate BMR formula for most people. The Harris-Benedict equation is a classic formula but may slightly overestimate calorie needs. The Katch-McArdle formula is based on lean body mass, making it more accurate for people who know their body fat percentage and are physically active.
Understanding TDEE Activity Levels
TDEE (Total Daily Energy Expenditure) is calculated by multiplying your BMR by an activity factor. Sedentary means office work with little exercise; Lightly Active means light exercise 1-3 days per week; Moderately Active means moderate exercise 3-5 days per week; Very Active means hard exercise 6-7 days per week; Extremely Active describes physical laborers or professional athletes.
FAQ
Q: What's the difference between BMR and TDEE?
A: BMR is the calories your body burns at complete rest, while TDEE is your total daily calorie burn including all activities. To lose weight, consume fewer calories than your TDEE; to gain weight, consume more than your TDEE.
Q: Which BMR formula is most accurate?
A: The Mifflin-St Jeor equation is considered the most accurate BMR formula by the American Dietetic Association. However, if you know your body fat percentage, the Katch-McArdle formula may be more accurate as it's based on lean body mass rather than total weight.
Q: How can I increase my BMR?
A: Building muscle mass is the most effective way, as muscle tissue burns more calories than fat. Additionally, regular exercise, adequate sleep, staying hydrated, and avoiding extreme dieting all help maintain a higher metabolic rate.
Q: Does BMR change with age?
A: Yes, BMR gradually decreases with age. Starting from age 20, BMR drops approximately 2%-3% per decade. This is mainly due to loss of muscle mass and hormonal changes. Therefore, maintaining an active lifestyle and balanced diet becomes increasingly important as you age.