BMR Calculator
Calculate your Basal Metabolic Rate
Details
This is the number of calories your body burns at rest to maintain normal body functions.
Understanding Your Basal Metabolic Rate (BMR)
Your Basal Metabolic Rate (BMR) is the foundation of all calorie calculations for weight loss, muscle gain, and fitness goals. It represents the minimum number of calories your body needs to maintain vital functions like breathing, circulation, cell production, and nutrient processing while at complete rest.
Whether you're trying to lose weight, build muscle, or simply maintain your current physique, understanding your BMR is essential. This calculator uses the scientifically-validated Mifflin-St Jeor equation, which is considered the most accurate formula for calculating BMR in healthy adults.
Key fact: Your BMR accounts for 60-75% of your total daily calorie burn, making it the largest component of your metabolism. The remaining 25-40% comes from physical activity and the thermic effect of food (calories burned digesting food).
How to Use This Calculator
Select your biological gender (affects BMR calculation due to muscle mass differences)
Enter your age in years (BMR decreases approximately 2% per decade after age 20)
Input your height in feet and inches or centimeters
Enter your current weight in pounds or kilograms
View your BMR - the minimum calories your body needs at complete rest
Multiply by your activity level to get TDEE (Total Daily Energy Expenditure) for actual calorie needs
Pro Tips
- •Measure weight in the morning after using the bathroom for most accurate results
- •Never eat below your BMR - this can slow metabolism and cause muscle loss
- •Recalculate BMR every 10-15 lbs of weight loss to adjust calorie targets
- •For weight loss: eat between BMR and TDEE (typically TDEE minus 500 calories)
- •Track progress weekly and adjust calories based on results, not just the calculator
- •Consider body composition - muscle mass increases BMR significantly
BMR Formula for Men
BMR = (10 × weight) + (6.25 × height) - (5 × age) + 5Where:
weight= Body weight in kilogramsheight= Height in centimetersage= Age in years+5= Male constant (accounts for higher muscle mass)Example:
weight= 80 kg (176 lbs)height= 180 cm (5'11")age= 30 yearsCalculation:
(10 × 80) + (6.25 × 180) - (5 × 30) + 5 = 800 + 1125 - 150 + 5Result: 1,780 calories/day
BMR Formula for Women
BMR = (10 × weight) + (6.25 × height) - (5 × age) - 161Where:
weight= Body weight in kilogramsheight= Height in centimetersage= Age in years-161= Female constant (accounts for lower muscle mass)Example:
weight= 65 kg (143 lbs)height= 165 cm (5'5")age= 28 yearsCalculation:
(10 × 65) + (6.25 × 165) - (5 × 28) - 161 = 650 + 1031 - 140 - 161Result: 1,380 calories/day
Frequently Asked Questions
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest to maintain vital functions like breathing, circulation, and cell production. It represents 60-75% of your total daily calorie burn. Knowing your BMR is crucial for weight loss because it helps you determine your minimum calorie needs and create an effective calorie deficit without slowing your metabolism.