Protein calculator
Muscle protein synthesis responds to a dose of roughly 0.4 grams per kilogram of bodyweight, and the response plateaus above that. For a 75 kg person that is around 30 grams a meal — so four meals of 30 grams does more than one meal of 120. It is the most practical finding in the whole protein literature and the one most often ignored.
General guidance for healthy adults. Anyone with kidney disease should take protein advice from a doctor, not from a calculator.
Protein needs scale with bodyweight and training. The health minimum is 0.8 g per kg; strength training warrants about 1.6 g per kg, and up to 2.2 g per kg when cutting. A 75 kg lifter therefore wants around 120 grams a day.
How much protein to eat
The 0.8 g per kg figure that appears on nutrition labels is a minimum to prevent deficiency, not an optimum for anyone training. Position stands from the sports nutrition societies land at 1.4 to 2.0 g per kg for people doing resistance work, and the upper end applies during a calorie deficit, when protein protects lean mass that would otherwise be lost alongside fat. Beyond about 2.2 g per kg there is no measurable further benefit for body composition, and the extra calories are better spent elsewhere.
Questions
0.8 g per kg is the health minimum; 1.6 g per kg for strength training; up to 2.2 g per kg while cutting.