Protein Target Calculator

Your body weight is multiplied by a protein-per-kilogram factor that depends on your activity level and goal — for example, 0.8-1.0 g/kg if you're sedentary, up to 1.6-2.2 g/kg if you're active or an athlete pursuing muscle gain or weight loss. The factor comes from the ISSN Position Stand on protein and exercise, not a single universal number, which is why the result is shown as a range rather than one figure.

Because protein needs increase specifically to protect lean mass during a calorie deficit. This calculator uses the same 1.6-2.2 g/kg range for weight loss as it does for muscle gain — under-eating protein during a deficit has a real, measurable cost: more of the weight lost comes from muscle rather than fat. The lower 1.2-1.6 g/kg range only applies at maintenance, when you're not restricting calories.

Yes — a meta-regression across 49 studies (Morton et al., 2018) found gains in muscle mass plateaued around 1.6 g/kg, with little added benefit even in people specifically training to build muscle, up to roughly 2.2 g/kg. That's why this calculator's ranges top out around there rather than climbing indefinitely: protein eaten well beyond that ceiling doesn't build muscle faster, it just displaces calories that could come from carbohydrate or fat.

Both matter, but they're separate levers. The daily gram target from this calculator is the foundation, but spreading it across 3-4 meals of roughly 20-40g each appears to stimulate more muscle protein synthesis over a day than eating the same total in one or two large meals. So hitting your daily number is necessary, and distributing it evenly across meals is a second, independent way to get more benefit from the same total.

People with chronic kidney disease should get individualized medical guidance rather than following these general-population ranges, since high protein intake changes the calculus for impaired kidney function. Pregnant or breastfeeding people and children/adolescents also have protein needs set separately from these adult, activity-based ranges. Outside of those situations, the ranges here reflect resistance-training and dieting research in generally healthy adults.