Calculator

How Much Protein Do I Need?

Personalised daily protein targets based on your weight, goal and the latest sports nutrition research.

Your Weight

Your Goal

Science

How This Calculator Works

The Formula

Protein requirements are expressed as grams per kilogram of bodyweight (g/kg/day). This calculator uses your total bodyweight, which is standard practice in published research and gives a reliable estimate for most people. Targets would be marginally more accurate against lean body mass, but that requires body composition data most people don't have.

Why Targets Differ by Goal

Protein needs shift significantly depending on what your body is being asked to do. A calorie surplus, a deficit, and a maintenance phase all create different demands on muscle protein synthesis and breakdown.

Maintain weight

1.2–1.6g/kg

Adequate to support muscle retention and general health with no active anabolic stimulus. The lower end covers sedentary individuals; the higher end suits those doing regular exercise.

Build muscle

1.6–2.0g/kg

Supported by the Morton et al. (2018) meta-analysis of 49 RCTs. Intakes above 1.62g/kg produced no statistically significant additional gains in lean mass — so more protein is not meaningfully better.

Lose fat

1.8–2.2g/kg

Higher protein during a deficit protects against muscle loss. Helms et al. (2014) found lean athletes in a deficit benefited from intakes at or above 2.3g/kg of lean body mass, justifying the elevated range.

Athletic performance

1.7–2.2g/kg

Endurance and team sport athletes have elevated protein turnover from training volume. ISSN and ACSM joint guidelines recommend 1.7–2.0g/kg, with strength athletes at the higher end.

The Research Behind the Numbers

The ranges used in this calculator are drawn from three primary sources in the sports nutrition literature:

Morton et al. (2018)

A systematic review and meta-analysis in the British Journal of Sports Medicine covering 49 randomised controlled trials and over 1,800 participants. The key finding: protein supplementation significantly increased muscle mass gains during resistance training, with a dose-response breakpoint at approximately 1.62g/kg/day. Beyond this point, additional protein produced no statistically significant increase in lean mass.

Stokes et al. (2018)

Challenged the 1.6g/kg ceiling for trained individuals in a calorie surplus, arguing that methodological constraints in earlier studies underestimated needs during active hypertrophy phases. Their modelling suggested intakes up to 2.2g/kg may be beneficial — underpinning the higher end of the build muscle range used here.

ISSN Position Stand — Stout et al. (2022)

The International Society of Sports Nutrition recommends 1.4–2.0g/kg for most exercising individuals, rising to 1.8–2.7g/kg for athletes in energy restriction. This position stand synthesises decades of research across strength, endurance and team sports, and directly informs the lose fat and athletic performance ranges in this calculator.

Meal Distribution

Total daily protein is the primary driver of results, but distribution has a secondary effect. Areta et al. (2013) demonstrated that spreading protein across 4 meals of roughly 40g each produced greater myofibrillar protein synthesis than the same total split into 2 larger meals or 8 smaller doses. The practical takeaway: aim for 3–4 meals each containing at least 0.4g/kg of bodyweight in protein (roughly 30–40g for most people), spaced 3–4 hours apart to keep muscle protein synthesis elevated throughout the day.

Important Note

These targets are population-level averages derived from controlled research settings. Individual response varies based on training age, genetics, gut health and overall diet quality. Older adults (50+) may benefit from intakes at the higher end of any given range due to anabolic resistance — the reduced sensitivity of ageing muscle to dietary protein. This calculator is for educational purposes and does not replace personalised advice from a registered dietitian or sports nutritionist.