BMR Calculator
Calculate Basal Metabolic Rate (BMR) - calories your body burns at rest. Use Mifflin-St Jeor or Harris-Benedict formula based on age, gender, weight, and height for metabolism estimation.
PopularEnter Your Information
Enter weight in kilograms
Enter height in centimeters
Your BMR Results
Your BMR is 1618 calories per day. This is the number of calories your body burns at complete rest to maintain vital functions like breathing, circulation, and cell production.
Calorie Burn Over Time
📊 Formula Used
Mifflin-St Jeor Equation:
(10 × weight) + (6.25 × height) - (5 × age) + 5
Where: weight in kg, height in cm, age in years
What's Next?
💡 Using Your BMR
Your BMR is just the starting point. To find out how many calories you burn with daily activities, you need to calculate your TDEE (Total Daily Energy Expenditure) by multiplying your BMR by your activity level:
- Sedentary (little/no exercise): BMR × 1.2
- Lightly Active (1-3 days/week): BMR × 1.375
- Moderately Active (3-5 days/week): BMR × 1.55
- Very Active (6-7 days/week): BMR × 1.725
- Extra Active (physical job + exercise): BMR × 1.9
👉 Use our TDEE Calculator for complete calorie needs based on your activity level!
Understanding Basal Metabolic Rate (BMR)
Your Basal Metabolic Rate (BMR) is the number of calories your body needs to perform basic, life-sustaining functions at complete rest. This includes breathing, circulating blood, controlling body temperature, cell growth and repair, and brain and nerve functions.
What Affects Your BMR?
- Body Composition: Muscle tissue burns more calories than fat tissue, even at rest
- Age: BMR typically decreases about 2% per decade after age 20
- Gender: Men generally have higher BMR due to greater muscle mass
- Height/Weight: Larger bodies require more energy for basic functions
- Genetics: Some people naturally have faster or slower metabolism
- Hormones: Thyroid and other hormones significantly affect BMR
How to Use Your BMR for Weight Management
- Maintain Weight: Consume calories equal to your TDEE
- Lose Weight: Create a deficit of 500-1000 calories below TDEE
- Gain Weight: Create a surplus of 300-500 calories above TDEE
- Never go below BMR: Eating below BMR can slow metabolism and cause health issues
The Mifflin-St Jeor Equation
This calculator uses the Mifflin-St Jeor equation, developed in 1990 and considered the gold standard for BMR calculation. It's more accurate than the older Harris-Benedict equation, especially for modern populations and overweight individuals.
Important Considerations
- BMR calculations are estimates; actual metabolism varies by individual
- Medical conditions can significantly affect BMR
- Medications may increase or decrease metabolic rate
- Very low calorie diets can lower BMR (starvation mode adaptation)
- BMR is highest in growing children and decreases with age
- For precise measurements, consider metabolic testing at a lab