BMR Calculator
Enter the required values below to run the educational estimation.
What is Basal Metabolic Rate (BMR)?
Your Basal Metabolic Rate is the metabolic floor of your energy expenditure. Even if you spent the entire day lying completely still in bed, your body would still consume this amount of energy simply to keep your organs functioning. BMR accounts for roughly 60% to 75% of the total daily energy burned by a typical sedentary individual.
Mifflin-St Jeor vs. Harris-Benedict
The Harris-Benedict equation was originally developed in 1919. In 1990, Mifflin and St Jeor updated the formula, creating a more accurate equation that reflects modern body compositions, lifestyle changes, and metabolic patterns. The Mifflin-St Jeor equation has been validated in numerous clinical studies as the most reliable predictor of resting energy requirements.
Factors That Influence Metabolism
Several biological parameters determine your metabolic rate. Lean muscle tissue consumes significantly more energy than fat tissue, meaning individuals with high muscle mass burn more calories even at rest. Additionally, BMR naturally declines with age due to muscle loss, and males generally register higher metabolic baselines than females of similar size.
When to Seek Urgent Medical Attention
- Rapid, unintended weight loss of over 10 pounds in a few weeks.
- Extreme fatigue, cold intolerance, or severe changes in heart rate.
- Severe dizziness or fainting episodes.
Frequently Asked Questions
BMR is the minimum number of calories your body requires to maintain vital life functions (such as breathing, circulation, cell production, and temperature regulation) while at complete rest in a temperate environment.
This tool uses the Mifflin-St Jeor equation, which is widely considered by clinical dietitians to be the most accurate standard formula for estimating resting energy expenditure in modern populations.
