How Much Protein Per Day Do You Actually Need?

The question of how much protein per day you need has a clear answer from the research — but it differs significantly by goal. The government's minimum RDA of 0.8g/kg/day is enough to prevent deficiency but falls well short of what's optimal for weight loss, muscle building, or healthy aging. This guide gives you the right number for your specific goal, a free calculator, and a practical breakdown of how to hit it across meals.

Protein Needs by Goal

The government RDA of 0.8g/kg is designed to prevent muscle wasting in sedentary individuals — not to support body composition goals. A 2020 meta-analysis of 49 studies found that protein intakes above 1.62g/kg produced no additional muscle mass benefits for resistance training individuals, suggesting 1.6–2.2g/kg covers nearly all scenarios [1].

For weight loss specifically, higher protein (1.8–2.4g/kg) during a calorie deficit is beneficial because it reduces muscle loss, suppresses hunger more effectively than carbs or fat, and raises the thermic effect of food (burning 20–30% of protein calories in digestion) [2].

Free Protein Calculator

How to Spread Protein Across the Day

Research shows muscle protein synthesis is maximised by spreading protein across 3–5 meals of 25–40g each, rather than consuming it in 1–2 large doses. A single meal can only use approximately 25–40g of protein for muscle building — the rest goes to other uses [3].

Best Protein Sources Ranked by Protein per 100 kcal