How the macro split calculator works
Protein first, always
The split is built in priority order: protein at 1.6–2.2 g/kg depending on goal (highest when cutting — its muscle-preservation job matters most in a deficit); then fat at a floor of 0.6–1.0 g/kg (hormonal health; never below ~20% of calories for extended periods); then carbs fill whatever energy remains — the training fuel and the most flexible lever.
The deficit, honestly sized
−20% of TDEE (about 500 kcal for most adults) targets ~0.5 kg/week — the pace that preserves muscle and sanity. Faster cuts work for higher body-fat percentages and fail for lean ones: below ~15% body fat, aggressive deficits are where muscle and training quality die. The "slow cut" option trades speed for adherence and is the right answer more often than the internet admits.
Per-meal grams are the deliverable
Daily totals are abstract; the plate is real. The calculator divides protein evenly across your meal count — the pattern that best saturates muscle-protein synthesis across the day — and shows what a training-day plate looks like. You do not need perfect distribution; you need roughly-even protein and total calories held over the week.
What the split will not do
No macro split overrides energy balance: the cut works because calories are below TDEE, not because carbs are timed. Food quality, fiber (aim 25–38 g), and adherence dominate any remaining optimization. The best split is the one you can repeat for twelve weeks.