BMR Calculator
Calculate your Basal Metabolic Rate (BMR) to understand your resting calorie needs.
Gender
Age (Years)
Weight in:
kg
Height in:
cm
Your BMR Is
Calories / Day
What is BMR? (Mifflin-St Jeor BMR Calculator)
Basal Metabolic Rate (BMR) is the number of calories your body needs to accomplish its most basic (basal) life-sustaining functions. This includes breathing, blood circulation, nutrient processing, and cell production. This tool is a Mifflin-St Jeor BMR calculator — every result is computed using the Mifflin-St Jeor equation, the formula most doctors, dietitians, and fitness apps treat as the modern standard for estimating resting calorie needs.
How is BMR used? (BMR to TDEE / Total Daily Energy Expenditure)
Once you know your BMR, you can calculate your Total Daily Energy Expenditure (TDEE) by multiplying your BMR by an activity factor: TDEE = BMR × activity multiplier. Knowing your TDEE helps you figure out how many calories you need to consume to lose, maintain, or gain weight. Use the BMR number from this page as the input to our TDEE calculator to get your full daily calorie target.
Example
A 30-year-old woman, 165cm tall and 60kg, has a BMR (Mifflin-St Jeor) of roughly 1,320 calories/day — the energy her body burns at complete rest, before any activity is factored in.
Common Use Cases
- Setting a calorie baseline before building a diet or fitness plan.
- Calculating TDEE (Total Daily Energy Expenditure) by combining BMR with an activity multiplier.
- Understanding how age, weight, and body composition affect metabolism.
- Comparing calorie needs using the Mifflin-St Jeor equation instead of older, less accurate formulas.
FAQs — BMR Calculator Guide
What is the Mifflin-St Jeor equation?
The Mifflin-St Jeor equation is the formula this calculator uses to estimate BMR. It is:
Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age(years) − 161
Published by Mifflin and St Jeor in 1990, it's widely regarded as more accurate than the older Harris-Benedict equation for most people, which is why it's the formula (sometimes abbreviated "MSJ equation") used by this BMR calculator.
Is BMR the same as the calories I burn in a day?
No — BMR is calories burned at complete rest. Your Total Daily Energy Expenditure (TDEE) is higher and includes activity, exercise, and digestion. TDEE = BMR × activity multiplier.
Which formula does this use?
The Mifflin-St Jeor equation, widely considered one of the more accurate BMR formulas for the general population.
Is this a Mifflin-St Jeor calculator?
Yes — every result on this page is computed with the Mifflin-St Jeor equation rather than the older (less accurate) Harris-Benedict formula.
How is BMR different from TDEE (Total Daily Energy Expenditure)?
BMR is your resting calorie burn from the Mifflin-St Jeor equation above. TDEE — your Total Daily Energy Expenditure — takes that BMR and multiplies it by an activity level (sedentary, lightly active, moderately active, very active) to estimate the calories you actually burn in a full day, including exercise and movement.