Protein Intake Calculator
The official minimum stops you becoming deficient. The optimum for someone who trains is roughly double it.
Where the numbers come from
The Recommended Dietary Allowance of 0.8 g/kg is widely misunderstood. It is the amount that prevents deficiency in 97.5 % of healthy sedentary adults — a floor below which harm occurs, not a target for someone trying to build or retain muscle.
| Situation | Target | Rationale |
|---|---|---|
| Sedentary adult | 0.8 g/kg | RDA — prevents deficiency |
| Recreationally active | 1.2 g/kg | Covers training turnover |
| Building muscle | 1.6 g/kg | Meta-analysed plateau for hypertrophy |
| In a calorie deficit | 2.0–2.4 g/kg | Protects lean mass when energy is scarce |
| Adult over 65 | 1.2–1.5 g/kg | Anabolic resistance raises the threshold |
The 1.6 g/kg figure comes from Morton and colleagues' 2018 meta-analysis of 49 studies, which found that additional protein produced no further gains in lean mass beyond roughly that point in resistance-trained individuals.
Why lean mass is the better basis
Adipose tissue has minimal protein requirements. Calculating from total body weight therefore overstates the need for anyone carrying substantial fat — at 35 % body fat, a total-weight calculation can overshoot by 50 g a day.
If you know your body fat percentage, enter it and the calculator switches to lean mass, which is the basis most sports nutrition research actually uses. Our body fat calculator will estimate it from tape measurements.
Distribution and timing
Total daily protein matters most. Distribution matters second, and timing matters least — the “anabolic window” of 30 minutes after training has not held up well in controlled research.
What does hold up is per-meal dosing. Muscle protein synthesis responds to a dose of roughly 0.4 g/kg per meal, or about 25–40 g for most adults, and additional protein in the same sitting is oxidised rather than used for building. Spreading intake across three or four meals therefore beats one very large serving, even at the same daily total. Older adults need a larger per-meal dose, closer to 40 g, because of age-related anabolic resistance.
Frequently asked questions
Is high protein bad for the kidneys?
Not in people with healthy kidneys. Controlled trials at intakes up to 2.5–3.3 g/kg over periods of months show no adverse effect on renal function. The caution originates from advice given to patients with existing kidney disease, for whom protein restriction is genuinely indicated, and was then generalised to everyone. If you have diagnosed kidney disease, follow your nephrologist's guidance.
Do plant proteins count the same?
Mostly, with one adjustment. Plant sources tend to be lower in leucine and less digestible, so a roughly 10–20 % higher total intake, and deliberate variety across legumes, grains and soy, closes the gap. Soy, pea and quinoa are complete or near-complete on their own.
Do I need protein powder?
No. It is a convenience, not a requirement. Whole foods cover the target perfectly well; powder is simply a cheap, fast way to add 25 g when cooking is not practical.