BMR Calculator
BMR Calculator
Biological sex affects the formula offset.
Basal Metabolic Rate (BMR) is the amount of energy your body needs to maintain basic physiological functions — breathing, circulation, cell production — while completely at rest. It typically accounts for 60-75% of total daily energy expenditure, making it the foundation of any calorie or weight-management plan.
This calculator applies the Mifflin-St Jeor equation, published in 1990 and now considered the most accurate widely-used BMR formula for the general population, replacing the older Harris-Benedict equation. It combines weight, height, age, and sex into a single linear formula, with a fixed offset depending on biological sex to account for differences in average body composition.
Dietitians and personal trainers use BMR as the starting point before applying an activity multiplier to estimate total daily calorie needs. Individuals tracking weight loss or gain use it to set a realistic calorie floor, since eating consistently below BMR for extended periods can slow metabolism and is generally discouraged without medical supervision.
- Mifflin-St Jeor Formula: Considered more accurate than the older Harris-Benedict equation for most modern populations.
- Rest-Only Estimate: BMR reflects calories burned with zero activity — it does not include exercise or daily movement.
- Foundation for TDEE: BMR is multiplied by an activity factor to estimate Total Daily Energy Expenditure (see our TDEE Calculator).
- Sex-Specific Offset: The formula adds +5 for men and -161 for women to reflect average differences in muscle mass and body fat percentage.
What is a normal BMR?
Most adults have a BMR between 1,300 and 2,000 calories per day, depending on weight, height, age, and sex. Larger, younger, and more muscular individuals typically have a higher BMR.
Should I eat exactly my BMR in calories?
No. BMR represents calories burned at total rest. Your actual daily calorie needs (TDEE) are higher once activity is factored in — use our TDEE Calculator to get that number.
BMR Calculator
Biological sex affects the formula offset.
Basal Metabolic Rate (BMR) is the amount of energy your body needs to maintain basic physiological functions — breathing, circulation, cell production — while completely at rest. It typically accounts for 60-75% of total daily energy expenditure, making it the foundation of any calorie or weight-management plan.
This calculator applies the Mifflin-St Jeor equation, published in 1990 and now considered the most accurate widely-used BMR formula for the general population, replacing the older Harris-Benedict equation. It combines weight, height, age, and sex into a single linear formula, with a fixed offset depending on biological sex to account for differences in average body composition.
Dietitians and personal trainers use BMR as the starting point before applying an activity multiplier to estimate total daily calorie needs. Individuals tracking weight loss or gain use it to set a realistic calorie floor, since eating consistently below BMR for extended periods can slow metabolism and is generally discouraged without medical supervision.
- Mifflin-St Jeor Formula: Considered more accurate than the older Harris-Benedict equation for most modern populations.
- Rest-Only Estimate: BMR reflects calories burned with zero activity — it does not include exercise or daily movement.
- Foundation for TDEE: BMR is multiplied by an activity factor to estimate Total Daily Energy Expenditure (see our TDEE Calculator).
- Sex-Specific Offset: The formula adds +5 for men and -161 for women to reflect average differences in muscle mass and body fat percentage.
What is a normal BMR?
Most adults have a BMR between 1,300 and 2,000 calories per day, depending on weight, height, age, and sex. Larger, younger, and more muscular individuals typically have a higher BMR.
Should I eat exactly my BMR in calories?
No. BMR represents calories burned at total rest. Your actual daily calorie needs (TDEE) are higher once activity is factored in — use our TDEE Calculator to get that number.