How the macro calculator works
The anchoring order
Protein in grams per pound of body weight (goal-dependent: 0.8–1.0), fat at its floor (0.3–0.35 g/lb; hormones and fat-soluble vitamins require it), carbs filling the remainder — except low-carb approaches, which invert the last step. This ordering means any calorie target produces a coherent split, and explains why percent-based macros (30/40/30 etc.) produce silly answers at extreme calories.
How exact do the numbers need to be?
Protein: hit it daily within ~10 g — it has real, dose-dependent jobs. Fat: stay above the floor, flex above it. Carbs: the residue, flexed by training volume and preference. Precision beyond that is meal-prep aesthetics; the physique-relevant errors live in total calories and protein, not in a 5-gram carb deviation.
Food-first execution
Translating grams to plates: a palm of protein ≈ 25–30 g, a cupped handful of carbs ≈ 25–30 g, a thumb of fat ≈ 8–10 g. Building 4 meals of palm-palm-thumb against your targets beats weighing chicken to the gram — and survives restaurants, travel, and weeks when the scale is in a drawer.