BMR Calculator
What your body burns at rest, via Mifflin-St Jeor.
Estimate how many calories your body burns at complete rest, using the Mifflin-St Jeor equation.
How this is calculated
Methodology & sources
- Primary formula: Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. "A new predictive equation for resting energy expenditure in healthy individuals." Am J Clin Nutr. 1990;51(2):241–7.
- Comparison equation (1984 revision): Roza AM, Shizgal HM. "The Harris Benedict equation reevaluated: resting energy requirements and the body cell mass." Am J Clin Nutr. 1984;40(1):168–82.
- Original 1919 equation: Harris JA, Benedict FG. "A biometric study of basal metabolism in man." Carnegie Institution of Washington, Pub. 279, 1919.
- Lean-mass option: McArdle WD, Katch FI, Katch VL. Exercise Physiology: Nutrition, Energy, and Human Performance. Wolters Kluwer / Lippincott Williams & Wilkins.
- Organ resting energy split: Elia M. "Organ and tissue contribution to metabolic rate." In: Kinney JM, Tucker HN, eds. Energy Metabolism: Tissue Determinants and Cellular Corollaries. Raven Press, 1992:61–79.
Privacy — how your data is handled
All math runs in your browser on your device. Nothing you type is sent to a server,
and saved results live only in this browser's local storage. Tools that use live
public data (food databases, weather) request only what they need to display.
👟 Practical toolkit tip — Simple Pocket Pedometer or Wrist Step Counter
Why it helps: Tracking daily step volume (7,500–10,000 steps/day) prevents subconscious NEAT drop-off when you are in a calorie deficit.
Pro tip: A 15-minute brisk walk after dinner adds ~1,600 steps and blunts post-meal blood glucose spikes.