How Much Protein Do You Really Need Per Day?

By Jesse · Last updated August 20, 2026

Protein recommendations range from 0.8 to over 2 grams per kilogram of body weight — a difference of more than double, all of it defensible, depending on which study you read and what you are trying to achieve. This guide is about where each of those numbers came from and how much confidence each one deserves. If you just want the grams for your body weight, the protein intake chart is a lookup table and the protein calculator will do the arithmetic.

The spread exists because two different questions get one answer

Almost every argument about protein comes from collapsing two questions into one:

• How little can I eat without becoming deficient? This is a clinical question about requirements, and it is what the official recommendation answers.
• How much helps me build or keep muscle? This is a performance question, answered by training trials, and its answer is roughly double the first.

Both numbers are correct. Quoting either one as "how much protein you need" without saying which question it answers is what makes the topic feel contested when it mostly is not.

Where each figure comes from

The right-hand column is the part worth reading. It is what the study actually measured, which determines what the number is good for:

The RDA measures a floor, and probably a low one

The 0.8 g/kg figure comes from nitrogen balance research: feed people measured amounts of protein, track nitrogen in and out, and find the intake at which the books balance. A 2003 meta-analysis of those studies put the average requirement near 0.66 g/kg; the RDA adds a margin for person-to-person variation, arriving at 0.8. At 80 kg that is 64 g a day.

Two things follow. First, it is by construction a deficiency threshold — the intake at which something stops going wrong, which is not the same as the intake at which things go best. Second, the method itself has been challenged. Studies using indicator amino acid oxidation, a different technique, consistently produce higher requirement estimates for the same kind of sedentary adults, in the region of 1.0 to 1.2 g/kg. That does not overturn the RDA, but it means the floor is unlikely to be lower than 0.8 and might be higher.

Where 1.6 g/kg comes from, and what it does not mean

The most useful single piece of evidence for people who train is a 2018 meta-regression pooling resistance-training trials that varied protein intake. It looked for the point where extra protein stopped buying extra lean mass, and found a breakpoint at about 1.6 g/kg — 128 g a day at 80kg. The International Society of Sports Nutrition's position stand lands in the same neighbourhood with a range of 1.4 to 2.0 g/kg.

Three qualifications matter more than the figure itself:

• It is a population average with a wide interval. The statistical range around that breakpoint extended to roughly 2.2 g/kg, which is why recommendations for athletes commonly go that high. The plateau is a blurred region, not a line.
• The plateau is about lean mass, not everything. Satiety, appetite control, and the composition of weight lost in a deficit are separate outcomes, and protein continues to matter for them above the point where hypertrophy gains flatten out.
• Beyond the plateau, added protein is not doing nothing bad — it is doing nothing. Excess intake in healthy people is not dangerous. It is simply spent for no return, and it displaces food that would have done something.

What a high target costs out of your calories

The reason protein targets get argued about at the top end is that protein does not arrive for free. At 4 kcal per gram, a target is also a claim on your calorie budget — and the tighter the budget, the bigger the claim. All figures below are for an80 kg adult:

The same 2.2 g/kg target is 27% of a 2,600 kcal day and 44% of a 1,600 kcal day, leaving only 896 kcal for all the carbohydrate and fat in the diet. That is workable if you plan for it and miserable if you do not. This is the real argument for not chasing the top of the range by default — not any risk from the protein itself. The macro calculator shows what is left once your protein target is taken out.

Where extra protein earns its place: a calorie deficit

If there is one situation where the higher end of the range is worth the calories it costs, it is dieting. When energy is restricted, the body draws on both fat and lean tissue, and the two variables that shift the balance toward fat are resistance training and protein intake. A controlled trial that fed young men either 1.2 or 2.4 g/kg during a steep deficit with hard training found the higher-protein group lost more fat and, unusually for a deficit, gained a small amount of lean mass. Reviews of lean athletes cutting weight recommend intakes at or above 2.2 g/kg for the same reason.

There is a second, more practical benefit: protein is the most satiating macronutrient, which makes a deficit easier to actually hold. A plan you stick to at 1.8 g/kg beats a plan you abandon at 2.4. See how many calories to eat to lose weight for setting the deficit itself.

One adjustment applies at higher body weights. Because these recommendations scale with total body weight, they produce impractical targets for someone carrying a great deal of fat mass — the target is being driven by tissue that does not need feeding. Scaling to lean body mass or to a realistic goal weight is the more sensible approach; the body fat calculator will estimate lean mass from tape measurements.

Two groups the standard numbers under-serve

• Adults over about 60. Muscle becomes less responsive to a given dose of protein with age, and age-related muscle loss has real consequences for independence. An international position paper recommends 1.0 to 1.2 g/kg for healthy older adults — above the RDA, below the training range.
• People eating mostly plant protein. The gram count is not the whole story: plant sources generally carry less leucine and a less complete amino acid profile per gram, so a slightly higher total and more variety across sources is the usual advice. This is a solvable problem, not an argument against plant-based diets.

What to actually do

1. Pick a rate from the question you are asking, not from the highest number you have read. Training and not dieting: 1.6 g/kg. Training and dieting: 1.8 to 2.2. Sedentary and not trying to change your body: 0.8 to 1.2.
2. Convert it once and remember the gram total. Use the protein calculator, then stop recalculating. It does not move day to day.
3. Check the total fits your calories before committing, using the table above or the macro calculator. A target that leaves no room for anything else will not survive contact with a week of real meals.
4. Put protein in every meal rather than at dinner. Roughly 30 to 40 g per meal across three or four meals is how most people reach a high total without noticing.
5. Read grams of protein, not grams of food. A 200 g chicken breast is not 200 g of protein. Take the figure from a label or a food database.

Common questions

These are general estimates for healthy adults, not medical advice. If you have kidney disease or another medical condition, are pregnant, or have a history of disordered eating, talk to a doctor or registered dietitian before changing your protein intake. See our methodology for the sources behind these ranges.