How much protein a day, as the published ranges actually state it — and they disagree by a factor of three, from the RDA’s floor to what people lifting in a deficit are told. You get the one that fits your week, the others beside it, and what it looks like as food.
Protein a day
98–131 g
What that looks like
| Who | g per kg | For you |
|---|
These are published population recommendations, not a prescription. Higher protein intakes are well tolerated by healthy kidneys — but if you have kidney disease, your protein intake is something your doctor sets, not a calculator. Pregnancy and breastfeeding have their own higher numbers, which are not on this page.
Recommendations checked 2026-09-23.
Quick answer: the RDA is 0.8 g of protein per kg of body weight a day — the amount that prevents deficiency. If you are training, the International Society of Sports Nutrition’s position stand puts you at 1.4 to 2.0 g/kg; if you are losing fat, 1.2 to 1.6 preserves lean mass better than 0.8 does; and if you are lifting while eating less, the published range goes to 1.8 to 2.7. For a 180 lb (82 kg) person that is anything from 65 g to 220 g a day, depending entirely on which question you are asking.
How to use it
Put your weight in, pick the line that describes your actual week, and you get the range that guideline publishes — not a single confident number, because none of them are published as one. Add your age and it applies the higher floor for over-65s; add your height and it will tell you when a per-kilogram rule is overshooting.
Why one calculator gives 65 g and another gives 200
Because they are quoting different bodies answering different questions, and most of them do not say which.
The RDA: 0.8 g/kg
This is the Recommended Dietary Allowance from the Institute of Medicine’s Dietary Reference Intakes — the intake that meets the needs of 97-98% of healthy adults. It is a floor for avoiding deficiency. It is not, and was never meant to be, the optimum for someone training, dieting or ageing.
Training: 1.4 to 2.0 g/kg
The ISSN’s 2017 position stand concludes that this range is sufficient for most exercising people to build and maintain muscle. It is roughly double the RDA and still sits inside the official 10-35% of calories range.
Losing fat: 1.2 to 1.6 g/kg
Eating less means losing some lean tissue along with the fat. Intakes in this range, compared with 0.8, have been shown to preserve lean mass and improve body composition during weight loss in young, middle-aged and older adults. This is the setting most people reading this site are actually in.
Lifting while dieting: 1.8 to 2.7 g/kg
The highest published range, for resistance-trained people in a deficit who want to keep as much muscle as possible. The leaner and more trained you are, the higher in it you go — the same reviews express it as 2.3 to 3.1 g per kg of fat-free mass, which is why a body-fat estimate is useful here.
Two adjustments worth knowing about
Over 65, the floor rises. The PROT-AGE group recommends 1.0 to 1.2 g/kg for older adults to hold on to muscle and function, and more when active or unwell — so if the guideline you picked is lower, this page uses PROT-AGE instead and says so.
At a BMI of 30 or more, a per-kilogram rule overshoots. Fat tissue needs very little protein, so multiplying a high body weight by 2.0 produces a number that is neither necessary nor easy to eat. Where height is given and BMI is 30 or above, this page also shows the figure at the weight a BMI of 25 would be. That is the convention clinicians use, and it is labelled as a convention rather than dressed up as an equation.
Spreading it across the day
Total daily protein matters most, but distribution helps: about 0.4 g per kg per meal across at least four meals is what the research supports for maximising the muscle-building response. In practice that is a protein source at every meal rather than 90 g at dinner — which is also much easier to eat.
Is a lot of protein bad for you?
For healthy kidneys, no: the fear comes from advice given to people who already have kidney disease, where protein intake genuinely is restricted and genuinely is a doctor’s decision. If that is you, this page is not the place to set it. For everyone else the practical limits are appetite, budget and boredom — and the fact that protein displaces other things on the plate, which is part of why it helps with a deficit in the first place.