BMR Calculator
The Basal Metabolic Rate (BMR) Calculator estimates your basal metabolic rate—the amount of energy expended while at rest in a neutrally temperate environment, and in a post-absorptive state (meaning that the digestive system is inactive, which requires about 12 hours of fasting).
Result
Daily calorie needs based on activity level
| Activity Level | Calorie |
|---|
Exercise: 15-30 minutes of elevated heart rate activity.
Intense exercise: 45-120 minutes of elevated heart rate activity.
Very intense exercise: 2+ hours of elevated heart rate activity.
Understanding Your Basal Metabolic Rate (BMR)
Your BMR represents the calories your body burns at complete rest to maintain basic functions like breathing, circulation, and cell production. Think of it as your body’s “idle mode” energy consumption – similar to how a parked car still uses some fuel to keep systems running.
Key Facts About BMR:
- Accounts for about 70% of daily calorie expenditure
- Varies based on body composition, age, gender, and genetics
- Is measured under strict resting conditions (after 12+ hours fasting)
- Forms the foundation for calculating your total daily energy needs
How We Calculate It:
Our calculator uses the most accurate formulas:
- Mifflin-St Jeor Equation (most accurate for general population)
- Harris-Benedict Equation (revised 1984 version)
- Katch-McArdle Formula (best for those who know body fat %)
What Affects Your BMR?
- Muscle mass (more muscle = higher BMR)
- Age (BMR decreases about 1-2% per decade after 20)
- Body size (larger bodies have higher BMR)
- Gender (men typically have higher BMR)
- Hormones and genetics
- Environmental temperature
Important Notes:
- Online calculators provide estimates only
- For precise measurement, consult a specialist
- Your actual needs may vary by up to 26% from calculations
- BMR is just one component of your total daily energy expenditure
Using Your Results:
Multiply your BMR by an activity factor (1.2-1.9) to estimate total daily calorie needs. Track your progress and adjust as needed, as individual variations exist beyond what formulas can predict.