Protein advice swings from the 0.8 gram RDA to bodybuilding folklore. The research sweet spots are well mapped by goal, and this calculator applies the right multiplier for yours.
Your visual report appears here
Fill in the form and press Calculate. You will get your number, an interpretation chip, and a personalized chart pack drawn instantly in your browser.
- Risk spectrum with your position marked
- Reference ranges from the original publication
- Shareable link, nothing stored
Scientific references
What the RDA really means
The 0.8 grams per kilogram recommendation dates from nitrogen balance studies designed to prevent deficiency, not to optimize health or performance. It is a floor below which muscle wasting begins, and roughly a third of older adults still fall under it. Modern research paints a richer picture in which the right intake depends on what you are asking your body to do.
The evidence by goal
Adults over 65 face anabolic resistance, muscles that respond sluggishly to protein, and expert groups now recommend at least 1.0 to 1.2 grams per kilogram to defend against age related muscle loss. Recreational lifters chasing growth plateau near 1.6 grams per kilogram according to the landmark 2018 meta analysis pooling 49 studies, with little extra benefit beyond that. During a calorie deficit the target climbs again, since protein shields lean mass when energy runs short, and intakes toward 2.2 grams per kilogram show the strongest muscle preservation in lean dieters.
Distribution beats totals
Hitting the daily number in one giant dinner underserves muscle. Protein synthesis responds maximally to doses of roughly 0.3 to 0.4 grams per kilogram per meal, so three to four evenly spaced feedings outperform the same total crammed into the evening. The practical pattern is a meaningful protein anchor at every meal, with the post training meal earning its reputation honestly.
Sources and the kidney question
Complete proteins from dairy, eggs, fish, and soy carry the full amino acid set, while plant mixes reach the same destination with slightly larger portions. For people with healthy kidneys, intakes up to 2.2 grams per kilogram show no evidence of harm in studies lasting years. Established kidney disease is a different conversation that belongs with a nephrologist.