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Learn more →Macro Calculator (P/F/C grams from TDEE and goal)
Enter your stats, activity level, and goal (lose, maintain, gain). Get target daily calories plus grams of protein, fat, and carbs to hit them.
Fill in your stats to see your macro targets.
How it works
How macros are computed
Step 1: BMR via Mifflin-St Jeor — the most accurate of the simple formulas. Step 2: TDEE = BMR × activity factor (1.2 for sedentary up to 1.9 for athletes). Step 3: target calories = TDEE ± 500 for cutting/bulking, or TDEE for maintenance.
Step 4: split the calories. We use protein 30%, fat 30%, carbs 40% by default. Protein has a floor of 1.6 g/kg of body weight (the lower bound from sports nutrition reviews) — if 30% of calories is below that, we raise protein. Fat at 30% provides hormone support and satiety. The remainder goes to carbs.
Why these splits and floors
Protein: 1.6-2.2 g/kg is the evidence-based range for muscle protein synthesis in active people. Higher (up to 3 g/kg) doesn't hurt and may help during a deficit. Lower than 1.2 g/kg risks muscle loss during weight loss.
Fat: 0.6-1 g/kg is the minimum for hormone health. We target ~30% of calories which lands in this range for most people.
Carbs: fill the remaining calories. Carbs are the most flexible macro — your body can use protein and fat for energy, but performance in any high-intensity work suffers without sufficient carbs.
Adjusting for goals
Cutting: ~500 kcal/day deficit gives ~0.5 kg/week loss. Aggressive cuts (>750 kcal) increase muscle loss and metabolic adaptation. Keep protein high during a cut.
Bulking: 250-500 kcal/day surplus is the lean-bulk range. More aggressive surpluses add fat without much extra muscle.
Maintenance: useful between phases or for body recomposition. Slow but the safest place to live long-term.
Frequently asked questions
›Why a protein floor of 1.6 g/kg?
Sports nutrition research consistently shows muscle protein synthesis is maximized at 1.6-2.2 g/kg in active people. Below 1.2 g/kg risks muscle loss during a deficit.
›Can I customize the 30/30/40 split?
Not yet — we use a research-backed default. Custom splits may come later. For now, the protein number is the most important; fat and carb proportions are flexible.
›What if my macros add up to fewer calories than the target?
We display the macros derived from your target. Carbs round-fill the remainder, so totals should match within rounding error (a few kcal).
›Is 1 g/lb of bodyweight protein still recommended?
1 g/lb ≈ 2.2 g/kg, which is at the high end of the evidence-based range. It's safe and effective; not strictly necessary above 1.6 g/kg.
›Should I cut faster than 500 kcal/day?
For most people, no. Larger deficits accelerate weight loss but also muscle loss and metabolic adaptation. 500 kcal/day is a good balance.
›What about carb cycling or keto?
Keto and very-low-carb need a different macro split (often 75% fat, 20% protein, 5% carbs). This calculator uses a balanced split — keto-specific calculators are better for that approach.
›Does this account for body composition?
No — it uses total weight. If you have a lot of muscle or low body fat, true protein needs may be higher. Use lean body mass × 2.2 as an alternative protein target.
›Does the data leave my browser?
No. Calculation runs locally.
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DisclosureRelated tools
This tool is for general information only and is not medical advice, diagnosis, or treatment. Consult a qualified healthcare professional about your health.