Protein Calculator
Gains plateau around 1.6 g per kg of body weight in the best available meta-analysis, with the confidence interval reaching 2.2. Requirements rise in a deficit.
Your results
High protein intakes do not harm healthy kidneys. If you have kidney disease, protein intake is a medical question — ask your doctor.
Where the numbers come from
A systematic review and meta-analysis of 49 studies found that the benefit of protein for muscle and strength plateaued at around 1.6 g per kg of body weight per day, with the upper bound of the confidence interval at 2.2 g/kg.
In a deficit, requirements rise — reviews of fat-loss phases in trained athletes recommend 2.3–3.1 g per kg of fat-free mass, which lands around 2.0–2.6 g/kg of body weight for a reasonably lean person.
The per-meal figure, and the myth about it
You may have been told the body can only use 20–30 g of protein at a time. That came from studies which measured for only three to five hours. A 2023 study extended the window to twelve hours and compared 25 g against 100 g: the larger dose produced a greater and much more prolonged response, with no ceiling detected.
So the per-meal number above is a reasonable way to distribute intake, not a limit. If two large meals suit your life better than five moderate ones, that works.
Common questions
How much protein do I need to build muscle?
1.6–2.2 g per kg of body weight per day. More than that is not harmful and does little.
Do I need more protein on a plant-based diet?
Roughly 10–20% more, because plant protein is lower in leucine and slightly less digestible.
Is there a limit per meal?
Not in the way commonly claimed. Twelve-hour data found no upper limit to the anabolic response.
Do older adults need more?
Sit at the upper end of the range — the response to a given dose is blunted with age.
Related calculators
Track the numbers, not just calculate them
MyFitsy stores your weight, measurements and every session, so the figures above become a trend instead of a one-off.
