The calories you burn doing nothing
Your body’s baseline energy cost, before any movement.
Results update as you type 🥑
What BMR is — and why it matters
Your Basal Metabolic Rate is the energy your body spends keeping you alive at complete rest: breathing, circulation, cell repair and brain function. For most people it is the single largest part of daily calorie burn — typically 60–70%.
BMR is the foundation of every calorie target. Add activity and you get TDEE; eat below TDEE and you lose weight, above and you gain. Knowing BMR keeps you from cutting calories below a sensible floor.
We use the Mifflin–St Jeor equation, the most accurate general predictor in peer-reviewed comparisons. It needs only your sex, age, height and weight.
Common questions
What’s the difference between BMR and TDEE?
BMR is calories burned at complete rest. TDEE is BMR multiplied by an activity factor — the total you actually burn in a normal day.
Should I ever eat below my BMR?
Generally no. Sustained intake below BMR is hard to adhere to and risks muscle loss. Take your deficit from TDEE, not BMR.
Why does BMR fall as I lose weight?
A smaller body needs less energy to maintain. Recalculate every few kilograms so your targets stay accurate.
Is my data stored?
No. Everything is calculated in your browser. Nothing is sent to a server or saved.
Sources & references
- Mifflin MD, St Jeor ST, et al. “A new predictive equation for resting energy expenditure in healthy individuals.” Am J Clin Nutr. 1990;51(2):241–247.
- Frankenfield D, Roth-Yousey L, Compher C. “Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults.” J Am Diet Assoc. 2005;105(5):775–789.
This calculator provides estimates for general educational use and is not medical advice. Consult a qualified professional before making significant dietary changes.