Macro Calculator
Calculate your optimal daily macronutrient intake for your fitness goals
Macro calculator in 8 quick sections
1) Core idea
Estimate daily calories (TDEE), split them into protein, carbs, and fat by percent, then convert to grams using 4/4/9 kcal per gram without changing your training or goals.
2) Flow you can trust
- Inputs → age, sex, weight, height, activity, goal, macro %
- Units → lbs×0.45359237=kg; inches×2.54=cm (exact constants)
- BMR → Mifflin–St Jeor; TDEE = BMR × activity factor
- Goal → small surplus/deficit (this tool uses ±400 kcal by default)
- Macros → calories × percent ÷ 4/9 → grams/day
3) Sanity checks
- Macro % must total 100%.
- Protein typically 1.2–2.2 g/kg; fat rarely below 0.6–0.8 g/kg.
- Weight in lbs uses 0.45359237 exactly; height in inches uses 2.54 exactly.
4) Shortcuts
- Balanced start: 30/40/30 (P/C/F).
- Cut: raise protein a bit; bulk: raise carbs a bit.
- If unsure: set protein ≈1.6 g/kg, fat ≈0.9 g/kg, fill the rest with carbs.
5) Pitfalls
- Forgetting oils/sauces when tracking.
- Too aggressive deficits/surpluses that hide true macro needs.
- Letting % drift so total ≠ 100%.
6) Micro examples
- 2,200 kcal at 30/40/30 → Protein 165 g, Carbs 220 g, Fat 73 g.
- 1,800 kcal at 35/35/30 → Protein 158 g, Carbs 158 g, Fat 60 g.
7) Mini‑FAQ
- Which equation? Mifflin–St Jeor for BMR; 4/4/9 kcal/g for macros.
- Do I recalc on rest days? Optional—most keep weekly averages consistent.
- Change units? Yes—lbs↔kg and inches↔cm use exact constants.
8) Action tip
Run the calc, track for 2–3 weeks, then adjust calories by ±5–10% while holding protein steady and shifting carbs/fat as needed.