Turn your daily calories into protein, carb, and fat grams
| Split (C/P/F) | 2,400 cal: P / C / F | Best for |
|---|---|---|
| 45 / 25 / 30 | 150g / 270g / 80g | General health, endurance base |
| 40 / 30 / 30 | 180g / 240g / 80g | Classic Zone-style default, body recomposition |
| 35 / 35 / 30 | 210g / 210g / 80g | Fat loss with training (high protein) |
| 30 / 40 / 30 | 240g / 180g / 80g | Aggressive cut, bigger appetites to manage |
| 20 / 40 / 40 | 240g / 120g / 107g | Low-carb, insulin-resistant, satiety focus |
| 10 / 25 / 65 | 150g / 60g / 173g | Ketogenic (medical supervision for therapeutic use) |
The National Academies' Acceptable Macronutrient Distribution Ranges (AMDR): protein 10–35%, carbohydrates 45–65%, fat 20–35%. Everything except deliberate keto and very-high-protein cuts sits inside them.
| Body weight | 0.7 g/lb (RDA-ish) | 1.0 g/lb (building) | 1.4–2.0 g/kg range (evidence-based) |
|---|---|---|---|
| 120 lb | 84g | 120g | 76–109g |
| 150 lb | 105g | 150g | 95–136g |
| 180 lb | 126g | 180g | 114–163g |
| 210 lb | 147g | 210g | 133–191g |
| 250 lb | 175g | 250g | 159–227g |
The RDA is 0.8 g per kg (0.36 g/lb), a minimum to prevent deficiency, not an athletic target. For building muscle, reviews converge on 1.4–2.0 g per kg daily; above ~1 g/lb the benefit flattens.
Calories are the budget; macros are how you spend it. Protein and carbs cost 4 calories a gram, fat costs 9, and alcohol (the forgotten fourth macro) costs 7. This calculator does the division both ways people actually plan: by percentage split, or by anchoring protein to body weight and letting carbs take the leftovers.
Grams = calories × percentage ÷ calories-per-gram. So protein grams = calories × P% ÷ 4, carb grams = calories × C% ÷ 4, fat grams = calories × F% ÷ 9. The grams must re-add to your calorie total, and the calculator shows that check line every time. In per-pound mode: protein grams = weight × g/lb, fat grams = calories × F% ÷ 9, and carbs = (calories − protein×4 − fat×9) ÷ 4.
Start from your calorie target: if you don't have one, the calorie deficit calculator or calorie calculator will produce it from your stats. Pick a preset or dial custom percentages; the grams update as you type. Training hard? Anchor protein first (per-pound mode) and treat carbs as the performance lever that's left over.
2,400 calories at 40/30/30. Carbs: 2,400 × 0.40 ÷ 4 = 240g. Protein: 2,400 × 0.30 ÷ 4 = 180g. Fat: 2,400 × 0.30 ÷ 9 = 80g. Check: 240×4 + 180×4 + 80×9 = 960 + 720 + 720 = 2,400. Exact, no rounding drift, because 30% of 2,400 divides cleanly by both 4 and 9.
A 180-lb lifter cutting on 2,224 calories wants 0.8 g/lb of protein and 30% of calories from fat. Protein = 180 × 0.8 = 144g (576 cal). Fat = 2,224 × 0.30 ÷ 9 = 74g (668 cal, using 74.1g rounded). Carbs get what's left: (2,224 − 576 − 667) ÷ 4 = 245g. That's a 44/26/30 split in percentage terms, and the extra carbohydrate is exactly why anchor-protein mode beats a fixed ratio for people who train.
Multiply your daily calories by each percentage, then divide by calories per gram: 4 for protein, 4 for carbs, 9 for fat. On 2,400 calories at 40% carbs, 30% protein, 30% fat, that's 2,400 × 0.40 ÷ 4 = 240g carbs, 2,400 × 0.30 ÷ 4 = 180g protein, and 2,400 × 0.30 ÷ 9 = 80g fat. The grams always have to add back to your calorie total: 240×4 + 180×4 + 80×9 = 2,400.
Protein is the lever that matters. Set protein at 0.7 to 1 g per pound of body weight to protect muscle and control hunger, put fat at 20 to 35% of calories for hormones and fat-soluble vitamins, and let carbs fill the rest. For a 180-lb man eating 2,224 calories, a 35/35/30 split works out to about 195g protein, 195g carbs, and 74g fat.
The National Academies' Acceptable Macronutrient Distribution Ranges allow protein 10–35%, carbs 45–65%, and fat 20–35% of calories, and any split inside those bands can be healthy. The band that fits you depends on training, preference, and what you'll actually eat. Extremely low carb (keto's 5–10%) sits outside the AMDR and is a therapeutic tool more than a default.
The evidence-based range for building muscle is about 1.4 to 2.0 g per kg of body weight (0.6 to 0.9 g per lb) per day, spread across 3 or 4 meals with 20 to 40g each. More than that isn't harmful for healthy kidneys, but returns flatten. A 180-lb lifter lands around 115 to 160g a day; the 2.2 g per lb crowd is paying for expensive urine.
Alcohol is the fourth macro at 7 calories per gram, and tracking apps usually log it separately. It's not essential to fit it into the P/C/F split, but those calories do come out of your budget. A practical habit: count each drink as roughly the calories on the label and pull them from your carb or fat allowance for the day.
Keep protein identical every day; muscle repair happens on rest days. Carbs can float with activity, dropping 50 to 100g on a rest day and rising before hard sessions, while fat stays roughly steady. Some people prefer one flat number for simplicity, which is fine; the weekly average drives results more than daily precision.