About this calculator
Macronutrients (macros) are the three energy-providing food categories: protein (4 cal/g), carbohydrates (4 cal/g), and fat (9 cal/g). At any calorie target, you can split macros in different ratios — and the split affects body composition, satiety, performance, and adherence. This calculator generates target grams from calories, goal, and protein-per-pound target.
Protein first
Protein is the macro with the most agreed-on target. For body recomposition, sports performance, and aging well, 0.7–1.0 g/lb bodyweight (1.5–2.2 g/kg) is the well-supported range. On a cut, protein protects lean mass. On a bulk, protein supports muscle synthesis. At any goal, hitting the protein target first is the highest-leverage dietary lever.
Fat — minimum then optional
Dietary fat supports hormone production (especially testosterone, estrogen, and other steroids). Minimum is roughly 0.3 g/lb to support endocrine function — going below for extended periods can suppress hormones. Above that, fat is flexible; high-fat (ketogenic, 70%+ of calories) and moderate-fat (25–35%) both work.
Carbs — the flexible remainder
After protein and fat are set, remaining calories go to carbs. Carbs are the primary fuel for high-intensity training and the body’s preferred energy source for athletes. Low-carb works for many people on a fat-loss cut (less hunger), but for athletes pushing high training volumes, sub-100g/day carbs typically hurts performance.
Default splits by goal
- Cut — ~40% protein, 30% fat, 30% carbs. High protein protects muscle in deficit.
- Maintain — ~30% protein, 30% fat, 40% carbs. Balanced.
- Bulk — ~25% protein, 25% fat, 50% carbs. Higher carbs to fuel training; protein and fat satisfy minimums.