Resting energy
BMR Calculator
Estimate your basal metabolic rate — the energy your body uses at rest — using the Mifflin-St Jeor equation, the prediction equation most widely used in practice.
Your information stays on this device. Nothing you type is sent to a server, saved to an account or added to analytics.
Your results
What BMR is used for
BMR is the foundation of every other number on this site. Multiply it by an activity factor and you have a maintenance estimate; adjust that for a goal and you have a calorie target. On its own it is a floor, not a plan, and eating at your BMR is not a recommended strategy.
For the derivation and the sources behind the equation, see our methodology page, or read what BMR really measures and why your number is an estimate.
Suggested next calculators
- Run every number in the all-in-one fitness calculator
One set of inputs, every number: BMI, BMR, maintenance, target and macros.
- Open the tdee calculator
Estimate the total energy you use across a normal day.
- Open the calorie calculator
Turn your maintenance estimate into a daily calorie target.
Relevant guides
- How Many Calories Should I Eat Per Day? Calculate, Test and Adjust Your Starting Target
Learn how to estimate your daily calorie target for maintenance, fat loss or weight gain, why a fixed 500-calorie cut does not suit everyone, and how to calibrate your number over 14 days.
- BMR vs TDEE: What’s the Difference, and Which Number Should You Use?
BMR is the energy your body burns at complete rest; TDEE adds all movement on top. Neither number is your calorie intake target — that requires choosing a goal. This guide explains the difference clearly.
- Is BMI Accurate? What It Measures, What It Misses, and What to Check Next
Understand what BMI actually measures, why it is still used in medicine, its key limitations for athletes and diverse populations, and a practical five-layer framework to interpret your result.