Calorie calculator: BMR, TDEE & macros
Results update as you type, with the formula and your numbers plugged in.
The formula
Example: 35-year-old man, 5′10″ (177.8 cm), 180 lb (81.6 kg) → 1,758 kcal BMR; moderately active (×1.55) TDEE 2,725 kcal.
Setting a target
A 500 kcal daily deficit is the common rule of thumb for about 1 lb (0.45 kg) per week. Lifting weights and eating around 1.6 g/kg protein helps protect lean mass (the general adult RDA is 0.8 g/kg).
FAQ
BMR vs TDEE?
BMR is energy burned at complete rest; TDEE multiplies it by an activity factor to estimate total daily burn. Set diet targets from TDEE.
Why Mifflin–St Jeor?
A 2005 ADA systematic review (Frankenfield et al.) found it the most accurate RMR equation for healthy adults. Revised Harris–Benedict is shown for comparison.
How accurate is it?
Expect roughly ±10% individual error. Track your weight for 2–3 weeks and adjust by 100–200 kcal.
Why a minimum floor?
Loss targets are not shown below 1,200 kcal (women) / 1,500 kcal (men) to avoid recommending very low intakes.
Can I save or share my result?
Your inputs live in the URL as you type. Use “Share result link” to reopen the exact result.
Sources
- 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. doi:10.1093/ajcn/51.2.241
- Frankenfield D, et al. Systematic review of RMR prediction equations — Mifflin–St Jeor most accurate. J Am Diet Assoc 2005;105(5):775–789. doi:10.1016/j.jada.2005.02.005
- Roza AM, Shizgal HM. Revised Harris–Benedict. Am J Clin Nutr 1984;40(1):168–182. doi:10.1093/ajcn/40.1.168
- Protein 1.6 g/kg (resistance-training adults): Morton RW, et al. "A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults." British Journal of Sports Medicine (Br J Sports Med) 2018;52(6):376–384. doi:10.1136/bjsports-2017-097608
- Activity multipliers (1.2–1.9) are conventional estimates; individual variation is large.
Formulas and sources checked 2026-10-16. Not medical advice. Pregnant, nursing, under 18 or with a medical condition — ask a professional.