Macro calculator
Protein, fat and carb grams for your calorie goal — protein-first split.
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
How are the macros split?
Protein is set first (1.6 g/kg, the strength-training level), fat at 25% of calories, and carbs fill the rest.
How do I convert calories to grams?
Protein and carbs have 4 kcal per gram; fat has 9 kcal per gram.
Do I need low carb to lose weight?
Total calorie deficit drives fat loss. Choose a split you can stick to and that keeps you full.
What is the minimum fat intake?
Around 20% of calories or more is commonly advised for hormones and fat-soluble vitamin absorption.
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.