BMR Calculator
Use this free BMR calculator to estimate your Basal Metabolic Rate, the number of calories your body burns at rest for basic life functions.
Basal metabolic rate estimate
What Is BMR?
Basal Metabolic Rate, or BMR, estimates the calories your body uses at rest. These calories support essential functions such as breathing, circulation, body temperature control, cell repair and normal organ function.
BMR is the resting foundation. To estimate daily maintenance calories, BMR is multiplied by an activity level to produce TDEE.
How the BMR Calculator Works
This page uses the Mifflin-St Jeor equation as a practical educational estimate. The formula uses sex, age, height and weight.
Mifflin-St Jeor Formula
For men: BMR = 10 × weight in kg + 6.25 × height in cm − 5 × age + 5.
For women: BMR = 10 × weight in kg + 6.25 × height in cm − 5 × age − 161.
BMR vs RMR vs TDEE
BMR estimates calories used at complete rest. RMR is similar but often measured under slightly less strict conditions. TDEE includes BMR plus activity and daily movement.
What Affects BMR?
BMR can be affected by body size, lean mass, age, sex, genetics, hormones, health status, medication and recent weight change.
Limitations and Safety
This calculator is for educational planning only. It is not medical advice. People with medical conditions, pregnancy, very low body weight, eating-disorder risk or major diet concerns should seek professional guidance before significant diet changes.
BMR Calculator FAQ
What is a good BMR?
There is no single good BMR. A larger or more muscular person usually has a higher BMR than a smaller person.
Can I eat below my BMR?
Some diets may go below BMR, but doing so can be difficult and may not be appropriate for everyone.
Should I use BMR or TDEE for calories?
Use TDEE for daily calorie planning because it includes activity. BMR is the resting baseline.