BMR Calculator
Calculate your Basal Metabolic Rate using the accurate Mifflin-St Jeor equation
Calculate Your Basal Metabolic Rate
BMR decreases with age due to muscle mass loss
Males typically have higher BMR due to muscle mass differences
Higher weight generally increases BMR
Taller individuals typically have higher BMR
Your BMR Results
Formula: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age(years) + 5
Calculation: BMR = 10 × 0.0 + 6.25 × 0.0 - 5 × 0 + 5 = 0 kcal/day
Equation: Mifflin-St Jeor (most accurate for general population)
Example Calculations
Male Example
Age: 30 years
Weight: 80 kg (176 lbs)
Height: 180 cm (5'11")
BMR: 10×80 + 6.25×180 - 5×30 + 5 = 1,880 kcal/day
Female Example
Age: 25 years
Weight: 60 kg (132 lbs)
Height: 165 cm (5'5")
BMR: 10×60 + 6.25×165 - 5×25 - 161 = 1,402 kcal/day
BMR vs RMR
BMR (Basal Metabolic Rate)
Energy needed in complete rest, fasting state. Measured in laboratory conditions.
RMR (Resting Metabolic Rate)
Energy needed at rest, including food digestion. Typically 10-15% higher than BMR.
Factors Affecting BMR
Body Composition
More muscle = higher BMR
Genetics
Family history affects metabolic rate
Body Temperature
Fever increases BMR by ~13% per °C
Physical Activity
Regular exercise builds muscle
Hormones
Thyroid hormones regulate metabolism
BMR Tips
BMR accounts for 60-75% of total daily calories
Mifflin-St Jeor is most accurate for general population
BMR decreases ~1-2% per decade after age 30
Muscle tissue burns 6x more calories than fat
Very low calorie diets can slow metabolism
Understanding Basal Metabolic Rate (BMR)
What is BMR?
Basal Metabolic Rate (BMR) is the amount of energy your body needs to maintain basic physiological functions while at complete rest. This includes breathing, circulation, cell production, nutrient processing, and brain and nerve functions.
Why is BMR Important?
- •Foundation for calculating daily calorie needs
- •Essential for weight management planning
- •Helps optimize nutrition and fitness goals
- •Monitors metabolic health changes over time
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
Why Mifflin-St Jeor?
- Most Accurate: ±10% error rate vs ±20% for older formulas
- Modern Data: Based on current population studies
- Widely Accepted: Recommended by nutrition professionals
- Validated: Extensively tested across diverse populations
Note: BMR estimates are starting points. Individual variation can be significant.
BMR Formula Comparison
| Formula | Year | Accuracy | Best For |
|---|---|---|---|
| Mifflin-St Jeor | 1990 | Highest (±10%) | General population |
| Harris-Benedict (Revised) | 1984 | Good (±15%) | Historical comparison |
| Katch-McArdle | 1975 | Excellent (±5%) | Athletes with known body fat% |
| Harris-Benedict (Original) | 1919 | Lower (±20%) | Historical interest only |
Medical Disclaimer
This BMR calculator provides estimates for educational and informational purposes only. Individual metabolic rates can vary significantly due to genetics, medical conditions, medications, and other factors. For medical advice regarding metabolism, weight management, or specific health concerns, consult with a healthcare professional, registered dietitian, or certified nutrition specialist. This tool should not replace professional medical assessment or personalized nutrition guidance.