Daily Protein Intake Calculator

Formula

How this is calculated

Protein requirements are most accurately expressed relative to body weight, in grams per kilogram (g/kg) per day. The US Recommended Dietary Allowance (RDA) sets a minimum of 0.8 g/kg for sedentary adults — enough to prevent deficiency but not optimal for physically active people. Sports nutrition bodies, including the ISSN (2017 Position Stand) and the joint ACSM/AND/DC statement (2016), recommend higher intakes for people who exercise regularly.

This calculator uses four evidence-based goal categories. Maintenance (0.8–1.2 g/kg) covers sedentary adults and light activity. Endurance sport (1.2–1.6 g/kg) supports muscle repair and glycogen synthesis in runners, cyclists and swimmers. Muscle building (1.6–2.2 g/kg) maximises muscle protein synthesis during strength training; research shows negligible additional benefit above 2.2 g/kg for most people. Weight loss (1.2–1.8 g/kg) helps preserve lean mass while in a caloric deficit — a higher rate compensates for the reduced anabolic signal from lower total calories.

Protein provides 4 kcal per gram (the Atwater factor). The per-meal estimates assume the total is spread evenly across meals; current evidence suggests 0.3–0.4 g/kg per meal optimally stimulates muscle protein synthesis, so dividing the daily total across 3–5 meals is preferable to consuming it all at once. Individual responses vary with age, training status, gut health and total calorie intake — treat these ranges as evidence-based starting points and adjust based on progress.