How much protein to build muscle?

How many grams of protein a day to build muscle

Researchers state protein as grams per kilogram of body weight, because bigger bodies hold more muscle. To use the figures, divide your weight in pounds by 2.2 to get kilograms, then multiply. The table does the sums at three points from the studies: 1.4 g per kg, the low end of the range the International Society of Sports Nutrition (ISSN) gives for people who exercise; 1.6 g per kg, where added gains leveled off in pooled trials; and 2.0 g per kg, the top of the ISSN range.^1,2

Each figure is a total for the whole day from every food and drink, not the amount in a scoop of powder. The studies counted total intake.²

The International Society of Sports Nutrition says 1.4 to 2.0 g of protein per kg of body weight a day is enough for most people who exercise to build and keep muscle. NIH gives a similar range for athletes, 1.2 to 2.0 g per kg.^1,3

In a pooled analysis of 49 training trials, protein supplements added no more lean mass once total protein intake passed about 1.6 g per kg of body weight a day. The estimate was uncertain, with a likely range of about 1.0 to 2.2 g per kg.²

Is the 0.8 g per kg RDA enough for building muscle?

The Recommended Dietary Allowance (RDA) for protein is 0.8 g per kg of body weight a day for healthy adults and 0.85 g per kg for teens. The ISSN says this amount is not enough for people in regular training.^1,3

At 70 kg, 0.8 g per kg is 56 g a day, half of the 112 g that 1.6 g per kg gives. Sports nutrition groups give a separate, higher range for people who train.^1,3

Does more protein always mean more muscle?

A 2022 review of 74 randomized trials in healthy adults found that eating more protein gave a small extra gain in lean mass for people doing resistance training. The gain was clearest at 1.6 g per kg or more in adults under 65, and at 1.2 to 1.59 g per kg in adults 65 and over. For lower-body strength the extra was slight, and for handgrip strength it was unclear.⁴

Read together with the 1.6 g per kg result above, the research describes a ceiling on what extra protein adds, not a scale that keeps rising. Most of these trials also tested protein alongside a training program, so the results apply mainly to people who lift.^2,4

NIH says most athletes can probably get enough protein from food, and that protein powders and protein-fortified foods can help when they cannot. It sees no benefit in eating more than the recommended amounts.⁶

How much protein per meal to build muscle

For people who train, the ISSN suggests about 0.25 g of high-quality protein per kg of body weight per serving, or 20 to 40 g, containing 0.7 to 3 g of leucine.¹

At 0.25 g per kg, a 70 kg person's serving comes to about 18 g, and the 20 to 40 g range covers most body sizes. Four servings of 25 to 30 g add up to 100 to 120 g, which sits inside the daily ranges in the table.¹

The ISSN suggests spreading protein across the day in servings every 3 to 4 hours.¹

A meta-analysis of randomized trials found that protein taken within an hour before or after exercise did not significantly add strength or muscle size; total daily protein was the strongest predictor of muscle gain.^3,7

How much protein to build muscle for women

Most protein trials enrolled men, so the numbers for women come from pooled work and from a smaller set of studies. The ranges above are written per kilogram, which means they scale to any body weight.²

Far fewer protein trials have been done in women than in men. A pooled analysis that included 14 groups of women found no clear difference between the sexes, while the ISSN notes that women-only trials have not shown statistically significant gains in maximal strength.^1,2

In women aged 55 and over, whey protein combined with resistance training raised arm strength and leg lean mass more than placebo; without training it made no difference.⁸

In practice, the sourced approach is the same per-kg range applied to her own weight. At 60 kg, 1.4 to 2.0 g per kg is 84 to 120 g a day.^1,2

How much protein to build muscle after 65

An international expert group on protein in older people (PROT-AGE) recommends at least 1.0 to 1.2 g per kg of body weight a day for adults over 65, and 1.2 g or more for those who exercise.⁵

Older muscle needs a larger serving for the same response. An analysis cited in the 2018 meta-analysis found the response to one serving leveled off at about 0.24 g per kg in younger adults and 0.40 g per kg in older adults, and older men needed about 40 g of whey after exercise to reach the highest response.^1,2

The older-adult daily figures start lower than the 1.4 to 2.0 g per kg range, but the amount per serving is higher. In the analysis behind the entry above, older adults needed a larger serving than younger adults to get the same response.^2,5

Work out your own number

The protein per day calculator on this site multiplies your weight by each amount in this guide and shows the note the research gave for it. It reports what studies used and is not advice for you. The macro calculator shows protein next to carbohydrate and fat for a whole day of eating.

Who should ask a doctor before eating more protein

No tolerable upper intake level has been set for protein, because the risk of harm from protein in food is very low. NIH still advises caution with high intakes from foods and supplements combined, since data are limited, and reports no safety concerns up to about 2.0 g per kg a day.³

High-protein diets of two to three times the RDA do not appear to harm kidney function, bone health or hydration in healthy people, and trained adults eating up to about 3.3 g per kg a day for up to a year showed no change in kidney or liver markers. People with severely reduced kidney function may need to limit protein.^1,3,5

Ask your doctor before raising your protein if you have kidney disease or have been told to limit protein. Ask first too if you are pregnant, nursing or under 18, because the trials behind these ranges were done in adults.^1,3

Allergic reactions can occur. Milk, soy and peanuts are major food allergens, and peas, lentils, lupin and other legumes can also cause reactions, sometimes severe and sometimes in people already allergic to peanut.^9,10

Questions people ask

Sources

1. Jäger R, et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. Opened 2026-10-01.
2. Morton RW, et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br J Sports Med. 2018;52(6):376-384. Opened 2026-10-01.
3. National Institutes of Health, Office of Dietary Supplements. Dietary Supplements for Exercise and Athletic Performance: Fact Sheet for Health Professionals. Updated April 1, 2024. Opened 2026-10-07.
4. Nunes EA, Colenso-Semple L, McKellar SR, et al. Systematic review and meta-analysis of protein intake to support muscle mass and function in healthy adults. J Cachexia Sarcopenia Muscle. 2022;13(2):795-810. Opened 2026-10-11.
5. Bauer J, Biolo G, Cederholm T, et al. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. J Am Med Dir Assoc. 2013;14(8):542-559. Opened 2026-10-07.
6. Office of Dietary Supplements, National Institutes of Health. Dietary Supplements for Exercise and Athletic Performance: Fact Sheet for Consumers. Updated March 22, 2021. Opened 2026-10-07.
7. Schoenfeld BJ, Aragon AA, Krieger JW. The effect of protein timing on muscle strength and hypertrophy: a meta-analysis. J Int Soc Sports Nutr. 2013;10(1):53. Opened 2026-10-07.
8. Kuo YY, Chang HY, Huang YC, Liu CW. Effect of Whey Protein Supplementation in Postmenopausal Women: A Systematic Review and Meta-Analysis. Nutrients. 2022;14(19):4210. Opened 2026-10-07.
9. U.S. Food and Drug Administration. Food Allergies. Content current as of March 11, 2026. Opened 2026-10-07.
10. Abu Risha M, Rick EM, Plum M, Jappe U. Legume Allergens Pea, Chickpea, Lentil, Lupine and Beyond. Curr Allergy Asthma Rep. 2024;24(9):527-548. Opened 2026-10-07.