How much protein do you need?
Protein Calculator: How Much Protein Per Day?
Sources checked · 2 sources · By Anthony Falcone
Before you start
- If you have kidney disease, talk to your doctor before you raise your protein. People with kidney failure benefit from protein-restricted diets; the reassuring safety data on higher protein come from healthy, active people.1
- Also check with your doctor first if you have liver disease, are pregnant or breastfeeding, have a history of eating disorders, or are under 18. This calculator is for healthy adults.
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The short answer: If you exercise, 1.4–2.0 g of protein per kg of body weight a day is enough for most people to build and keep muscle. If you lift and eat less than you burn, 2.3–3.1 g per kg may help you hold on to lean mass. On average, intakes above about 1.6 g per kg added no further muscle in training studies.1,2
How the calculator works
- Don't train regularly: 0.8 g per kg a day, the recommended dietary allowance (RDA) the International Society of Sports Nutrition quotes. The Society says it is not enough for people in training.1
- Train to build or keep muscle: 1.4–2.0 g per kg a day, which the Society calls sufficient for most people who exercise.1
- Lift and eat in a calorie deficit: 2.3–3.1 g per kg a day, the higher range the Society says may be needed to keep lean mass in resistance-trained people while dieting.1
- Where gains level off: a meta-analysis of 49 trials with 1,863 people found no further gain in lean mass beyond about 1.62 g per kg a day on average, with a confidence interval from 1.03 to 2.20 g. The calculator shows this point so you can see where your range sits.2
- Per serving: about 0.25 g per kg of body weight, or 20–40 g, with servings spread roughly every 3–4 hours. Older adults may need around 40 g per serving.1
Example: at 70 kg and training, 1.4 × 70 = 98 g and 2.0 × 70 = 140 g, so 98–140 g a day, with servings of about 0.25 × 70 ≈ 18 g, or 20–40 g.1
How sure is this?
- The 1.62 g per kg plateau is an average across studies, and its confidence interval runs from 1.03 to 2.20 g, so your own point may sit higher or lower. Less research was done in women than in men.2
- Several authors of the position stand declare ties to companies that sell protein or supplements, such as research funding, consulting and advisory roles.1
- The calculator uses your actual body weight. The ranges are for healthy, exercising adults; they don't account for medical conditions.1
Common questions
How much protein do I need a day to build muscle?
For most people who exercise, 1.4–2.0 g per kg of body weight a day. On average, gains in lean mass stopped increasing at about 1.6 g per kg in a meta-analysis of 49 trials.1,2
Should I eat more protein when I'm cutting?
If you lift and eat less than you burn, the International Society of Sports Nutrition says 2.3–3.1 g per kg a day may be needed to keep as much lean mass as possible.1
How much protein should be in one meal?
About 0.25 g per kg of body weight, or 20–40 g, spread across the day roughly every 3–4 hours. Older adults may need closer to 40 g per serving.1
Is a high-protein diet bad for your kidneys?
In healthy, exercising people, reviews have found no sign of kidney or liver harm from higher protein intakes. People with kidney failure are different: they benefit from eating less protein, so ask your doctor.1
Sources
- Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition Position Stand: protein and exercise. Journal of the International Society of Sports Nutrition, 2017. Position stand. doi.org/10.1186/s12970-017-0177-8
- Morton RW, Murphy KT, McKellar SR, 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. British Journal of Sports Medicine, 2018. Meta-analysis. doi.org/10.1136/bjsports-2017-097608