How to Split Your Macros
Every calorie you eat comes from one of three macronutrients: protein (4 cal/g), carbohydrates (4 cal/g), or fat (9 cal/g). Your macro split determines what percentage of daily calories comes from each. The right split depends on your goal — losing fat, building muscle, or maintaining weight.
Cutting (40/30/30)
40% protein / 30% carbs / 30% fat. High protein preserves muscle during a calorie deficit. At 2,000 calories: 200g protein, 150g carbs, 67g fat. Most effective when combined with resistance training 3–4 times per week. Aim for 1.0–1.2g protein per pound of bodyweight while cutting.
Bulking (30/50/20)
30% protein / 50% carbs / 20% fat. Higher carbs fuel intense workouts and support recovery. At 3,000 calories: 225g protein, 375g carbs, 67g fat. Protein at 0.8–1.0g per pound is sufficient for muscle growth when you're in a calorie surplus.
Maintenance (30/40/30)
30% protein / 40% carbs / 30% fat. A balanced split for sustaining weight and performance. At 2,500 calories: 188g protein, 250g carbs, 83g fat. This is a solid default if you're not sure where to start.
Keto (25/5/70)
25% protein / 5% carbs / 70% fat. Extremely low carbs (under 50g) force your body into ketosis, burning fat for fuel. At 2,000 calories: 125g protein, 25g carbs, 156g fat. Requires strict tracking and a 1–2 week adaptation period.
Macro Splits by Goal
| Goal | Protein | Carbs | Fat | Best For |
|---|---|---|---|---|
| Cutting | 40% | 30% | 30% | Fat loss while preserving muscle |
| Bulking | 30% | 50% | 20% | Muscle gain with high energy |
| Maintenance | 30% | 40% | 30% | Sustaining weight and performance |
| Keto | 25% | 5% | 70% | Ketosis-based fat burning |
| High Protein | 45% | 30% | 25% | Maximum muscle retention |
How to Calculate Grams from Calories
Multiply your daily calories by the macro percentage, then divide by the calories per gram. Protein and carbs have 4 calories per gram. Fat has 9 calories per gram.
Example: 2,500 calories at 30% protein = 2,500 × 0.30 = 750 protein calories ÷ 4 = 188g protein per day. The same 2,500 at 30% fat = 750 fat calories ÷ 9 = 83g fat.
Common Mistakes
- Ignoring protein per pound: Percentages alone don't tell the full story. A 200lb person eating 1,500 calories at 30% protein gets only 113g — just 0.56g/lb, below the minimum for muscle preservation. Always check the g/lb number.
- Percentages that don't add to 100: If your macro percentages total 90%, you have 10% of your calories unaccounted for. If they total 110%, your actual calorie intake exceeds your target.
- Not adjusting for activity: Rest days and training days don't need the same carb intake. Consider cycling carbs higher on lifting days and lower on rest days while keeping protein constant.
- Copying someone else's macros: A 130lb person and a 220lb person on the same percentages will have wildly different g/lb ratios. Use your own bodyweight and calorie target.
For splitting other amounts by ratio, use our ratio calculator or percentage split calculator.