BMR Calculator
Your Basal Metabolic Rate (BMR) is the number of calories your body needs to function at rest. This calculator uses the Mifflin-St Jeor formula for an accurate estimation.
Your BMR Result
Enter your details to calculate the calories your body burns at rest.
What is Basal Metabolic Rate (BMR)?
Your Basal Metabolic Rate, or BMR, represents the minimum amount of energy (calories) your body needs to carry out its most essential functions while at complete rest. These functions include breathing, circulating blood, regulating body temperature, growing cells, and processing nutrients. In essence, it's the number of calories you would burn if you stayed in bed all day without moving.
How is BMR Calculated? The Mifflin-St Jeor Formula
While several formulas exist, this calculator uses the Mifflin-St Jeor equation. Developed in 1990, it is widely considered the most accurate BMR formula for the general population, having shown a higher degree of reliability than older formulas like the Harris-Benedict equation.
- For Men: BMR = 10 × weight (kg) + 6.25 × height (cm) - 5 × age (y) + 5
- For Women: BMR = 10 × weight (kg) + 6.25 × height (cm) - 5 × age (y) - 161
Our calculator performs all necessary unit conversions automatically if you choose to enter your details in Imperial units.
What's the Difference Between BMR and TDEE?
This is a common point of confusion. While BMR is your metabolism at rest, your Total Daily Energy Expenditure (TDEE) is the total number of calories you burn in a 24-hour period. TDEE accounts for your BMR plus the energy expended during physical activity and the thermic effect of food (digestion).
Think of it this way: TDEE = BMR + Activity Level Calories. Your BMR is the largest component of your TDEE, typically accounting for 60-75% of your total daily calorie burn. To estimate your TDEE, you can use our dedicated Calorie Calculator, which incorporates activity levels.
Why is Knowing Your BMR Important?
Understanding your BMR is the foundational step in managing your weight. It gives you a baseline for your body's energy needs. With this number, you can more accurately determine how many calories you need to consume to:
- Lose Weight: Create a calorie deficit by consuming fewer calories than your TDEE.
- Maintain Weight: Consume a number of calories roughly equal to your TDEE.
- Gain Weight: Create a calorie surplus by consuming more calories than your TDEE.