BMR calculator
Estimate your resting energy expenditure (basal metabolic rate).
Your details
Basal metabolic rate
1,699kcal/day
Calories your body burns at rest. Add activity for your maintenance needs:
These are estimates. Track what you actually eat — Caltrac reads your calories and macros straight from a photo.
What your BMR tells you
Your Basal Metabolic Rate (BMR) is the energy your body uses at complete rest just to keep you alive — breathing, circulation, cell repair, and maintaining body temperature. It typically accounts for 60–70% of the calories you burn each day.
This calculator uses the Mifflin–St Jeor equation to estimate BMR from your sex, age, height, and weight, then shows your maintenance calories at each activity level. BMR is the foundation of any calorie or macro target: once you know it, multiply by an activity factor to get your full daily needs.
These calculators provide general estimates for healthy adults and aren’t medical advice. They aren’t intended for children, during pregnancy, or for clinical use — speak to a healthcare professional for personalised guidance.
Frequently asked questions
What's the difference between BMR and TDEE?
BMR is what you burn at rest. TDEE is your BMR multiplied by an activity factor to account for movement and exercise — your actual daily calorie burn.
Should I eat at my BMR to lose weight?
Generally no. Eating at or below your BMR for long periods is very restrictive. Base a weight-loss target on a moderate deficit from your TDEE, not your BMR.
Why does BMR fall with age?
Metabolic rate tends to decline with age, partly due to loss of muscle mass. The Mifflin–St Jeor equation reflects this by subtracting calories for each year of age.