Estimate your Basal Metabolic Rate — calories burned at rest.
Health figures are processed locally and never stored.
How is BMR calculated?
Using the Mifflin-St Jeor equation: BMR = 10 × kg + 6.25 × cm − 5 × age + s, where s is +5 for males and −161 for females. BMR is the energy your body uses at complete rest; total daily needs are higher once activity is added. A 30-year-old male at 175 cm and 70 kg has a BMR of about 1,649 calories per day.
Understanding your result
BMR is the baseline; your total daily needs are higher once activity is included. Use the TDEE Calculator to add activity.
Formula and method
Mifflin-St Jeor: BMR = 10 × kg + 6.25 × cm − 5 × age + s, where s = +5 for males and −161 for females.
Assumptions and limitations
BMR here is a general estimate from a population equation, not medical advice, and individual metabolism varies with body composition, genetics and health. It reflects rest only and excludes activity. Use it as a baseline for orientation, and speak to a qualified professional before making significant changes to your diet or exercise.
Worked example
A 30-year-old male, 175 cm and 70 kg, has a BMR of about 1,649 calories per day.
How to use this tool
- Choose your gender and enter your age.
- Pick metric or imperial units.
- Enter your height and weight.
- Press Calculate.
Common mistakes to avoid
- Treating BMR as your full daily calorie need — it excludes activity.
About the BMR Calculator
Your Basal Metabolic Rate (BMR) is the energy your body uses at complete rest to keep functioning. This calculator uses the well-regarded Mifflin-St Jeor equation.
Who should use this tool
Anyone wanting a baseline for how much energy their body uses at complete rest, as a first step before adding activity for total daily needs. Useful for people planning nutrition or curious about their metabolism, using the widely regarded Mifflin-St Jeor equation from height, weight, age and sex.
Benefits
- Estimates resting energy use with the Mifflin-St Jeor equation
- Gives a clear baseline before activity is added
- Needs only height, weight, age and sex
- Free to use with no login wall
Practical use cases
- Finding your resting calorie baseline before adding activity
- Understanding what drives your metabolism at rest
- Feeding a starting figure into a TDEE estimate
- Tracking how the number shifts with weight change
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Frequently asked questions
Is BMR the same as TDEE?
No. TDEE is BMR multiplied by an activity factor and reflects your real daily energy use.
What does BMR actually measure?
Basal Metabolic Rate is the energy your body uses at complete rest simply to keep functioning, covering processes like breathing, circulation and cell maintenance. It does not include any movement or exercise. Because it is the largest part of daily energy use for most people, it forms the baseline for total daily needs.
Why does BMR differ between men and women?
The Mifflin-St Jeor equation applies a different constant for each sex, reflecting average differences in body composition such as muscle and fat proportions. This means two people of the same height, weight and age can have different estimated BMRs. The figure remains a general estimate rather than an exact measurement for any individual.