Basal Metabolic Rate (BMR) Calculator
Calculate your Basal Metabolic Rate (BMR) with our advanced BMR calculator. Determine your daily calorie needs for weight loss, maintenance, or muscle gain using proven scientific formulas.
More accurate for modern populations (recommended)
Most widely used, good for general population
Most accurate when body fat % is known
Basic Information
Body Measurements
Activity Level
Multiplier: 1.55x your BMR
Quick Tips
- BMR is your energy needs at complete rest
- TDEE includes your daily activities
- Results are estimates (±10-15% accuracy)
- Consult professionals for medical advice
What is Basal Metabolic Rate (BMR)?
A BMR calculator determines your Basal Metabolic Rate, which represents the number of calories your body needs to maintain basic physiological functions at rest. This includes breathing, circulation, cell production, nutrient processing, and protein synthesis.
Your BMR accounts for about 60-75% of your total daily energy expenditure, making it the largest component of your metabolism. Understanding your BMR through our BMR calculator is crucial for effective weight management and fitness planning.
BMR vs TDEE: Understanding the Difference
BMR (Basal Metabolic Rate)
- • Calories burned at complete rest
- • Includes only essential body functions
- • Measured in controlled laboratory conditions
- • Foundation for all calorie calculations
- • Used by our BMR calculator as the baseline
TDEE (Total Daily Energy Expenditure)
- • BMR + physical activity calories
- • Includes exercise and daily movement
- • Accounts for thermic effect of food
- • More practical for daily calorie planning
- • Calculated using BMR as the foundation
Basal Metabolic Rate Calculator Formulas and Methods
Harris-Benedict Equation (Revised)
For Men:
Basal Metabolic Rate = 88.362 + (13.397 × weight in kg) + (4.799 × height in cm) - (5.677 × age in years)
For Women:
Basal Metabolic Rate = 447.593 + (9.247 × weight in kg) + (3.098 × height in cm) - (4.330 × age in years)
Mifflin-St Jeor Equation
For Men:
BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5
For Women:
BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161
Note: The Mifflin-St Jeor equation is considered more accurate for modern populations and is the default method used in our BMR calculator.
Factors That Affect Your BMR Calculator Results
Age
Basal Metabolic Rate decreases by approximately 1-2% per decade after age 20 due to loss of muscle mass and metabolic changes.
Gender
Men typically have higher Basal Metabolic Rate than women due to greater muscle mass and different hormonal profiles.
Body Composition
Muscle tissue burns more calories than fat tissue, so higher muscle mass increases BMR significantly.
Genetics
Genetic factors can influence BMR by up to 20%, affecting how efficiently your body uses energy.
Hormones
Thyroid hormones, insulin, and other hormones significantly impact metabolic rate and BMR calculations.
Climate
Extreme temperatures can increase BMR as the body works harder to maintain core temperature.
How to Use Your Basal Metabolic Rate Calculator Results for Weight Management
Weight Loss
- • Calculate TDEE from BMR
- • Create 500-1000 calorie deficit
- • Aim for 1-2 pounds per week loss
- • Never eat below BMR for extended periods
- • Monitor progress and adjust accordingly
Weight Maintenance
- • Eat calories equal to your TDEE
- • Use BMR as minimum calorie floor
- • Adjust for activity level changes
- • Monitor weight trends weekly
- • Recalculate Basal Metabolic Rate as you age
Weight Gain
- • Add 300-500 calories to TDEE
- • Focus on lean muscle gain
- • Combine with strength training
- • Monitor body composition changes
- • Adjust Basal Metabolic Rate calculations as you gain
Converting Basal Metabolic Rate to Total Daily Energy Expenditure (TDEE)
Once you have your BMR from our Basal Metabolic Rate calculator, multiply it by your activity level to get your TDEE:
Sedentary (1.2)
Little to no exercise, desk job
Lightly Active (1.375)
Light exercise 1-3 days per week
Moderately Active (1.55)
Moderate exercise 3-5 days per week
Very Active (1.725)
Hard exercise 6-7 days per week
Extremely Active (1.9)
Very hard exercise, physical job
Frequently Asked Questions About BMR Calculator
How accurate is a BMR calculator?
Our BMR calculator using the Mifflin-St Jeor equation is accurate within ±10% for most people. However, individual variations in muscle mass, genetics, and health conditions can affect accuracy. For the most precise measurement, consider indirect calorimetry testing.
Should I eat below my BMR to lose weight faster?
No, eating significantly below your BMR can slow your metabolism, cause muscle loss, and lead to nutritional deficiencies. Instead, use your TDEE (BMR × activity level) and create a moderate deficit of 500-750 calories for sustainable weight loss.
How often should I recalculate my Basal Metabolic Rate?
Recalculate your BMR every 10-15 pounds of weight change, or every 3-6 months. Age, changes in body composition, and significant lifestyle changes can all affect your Basal Metabolic Rate calculator results.
Can I increase my BMR naturally?
Yes! Building muscle through strength training is the most effective way to increase BMR. Other factors include staying hydrated, getting adequate sleep, eating enough protein, and maintaining an active lifestyle.
Why do men have higher BMR than women?
Men typically have higher BMR due to greater muscle mass, larger body size, and different hormonal profiles. Testosterone promotes muscle development, which increases metabolic rate. Our Basal Metabolic Rate calculator accounts for these gender differences in its formulas.