BMR Calculator
Find your Basal Metabolic Rate
Free BMR Calculator
Your Basal Metabolic Rate with the Mifflin-St Jeor formula
Your Basal Metabolic Rate (BMR) is the number of calories your body needs just to keep you alive at complete rest, powering your heart, brain, lungs and other organs. This calculator uses the Mifflin-St Jeor equation, one of the most accurate for the general population, based on your gender, age, height and weight. BMR is the foundation of any calorie plan. To find your full daily needs including activity, use our daily calorie calculator. Everything is calculated privately in your browser.
Features
Accurate Formula
Uses the Mifflin-St Jeor equation for reliable results.
Calories at Rest
The energy your body uses doing absolutely nothing.
Pairs With TDEE
Links to the daily calorie calculator for your full needs.
Private & Free
No account and nothing leaves your device.
Formula & Activity Multipliers
Mifflin-St Jeor formula (kcal/day)
- Men: 10×weight + 6.25×height − 5×age + 5
- Women: 10×weight + 6.25×height − 5×age − 161
- Weight in kg, height in cm, age in years
- Example: 80 kg, 180 cm, 30-year-old man → 1,780 kcal
Multiply for daily needs (TDEE)
- Sedentary: BMR × 1.2
- Lightly active: BMR × 1.375
- Moderately active: BMR × 1.55
- Very active: BMR × 1.725
- Extra active: BMR × 1.9
Frequently Asked Questions
What is BMR?
Basal Metabolic Rate is the number of calories you burn at complete rest over 24 hours, just to keep essential functions running. It is usually the largest part of your daily calorie burn.
What is the difference between BMR and TDEE?
BMR is your calorie burn at rest. Total Daily Energy Expenditure (TDEE) is BMR multiplied by an activity factor to include movement and exercise. Use the daily calorie calculator for TDEE.
Which formula is used?
This tool uses the Mifflin-St Jeor equation, which research finds to be one of the most accurate BMR formulas for most people.
How can I use my BMR?
BMR is the starting point for planning calories. Multiply it by your activity level for maintenance calories, then adjust up or down to gain or lose weight.
Does BMR decrease with age?
Yes. As muscle mass declines, BMR drops roughly 1-2% per decade; regular resistance training slows this down significantly.
Is eating below my BMR a good idea?
Staying below BMR long-term isn't recommended — it can cost muscle and slow your metabolism. Set a moderate deficit from TDEE instead. This tool is informational, not medical advice.