Written by the Spacemilk team · Last updated October 2026

The RDA for protein is 0.8 grams per kilogram of body weight per day (about 0.36 grams per pound), which is roughly 54g for a 150-pound adult. People who lift weights or train regularly are usually advised to aim higher, around 1.4 to 2.0 g/kg, and expert groups recommend at least 1.0 to 1.2 g/kg for healthy adults over 65. Spreading that protein across your meals, at roughly 20 to 40g each, is a practical way to get there.

What is the RDA for protein?

The Recommended Dietary Allowance (RDA) for adults is 0.8 g of protein per kilogram of body weight per day. In the US tables that works out to 56g a day for the reference adult man and 46g for the reference adult woman (National Academies, Dietary Reference Intakes).

An RDA is the daily intake that meets the needs of nearly all (97 to 98 percent) healthy people in a group. So it's a reliable baseline for adequacy. It isn't a target designed for people trying to build muscle, and it isn't the number expert groups use for older adults. Both of those groups get higher recommendations, covered below.

To find your own RDA, multiply your weight in kilograms by 0.8. If you think in pounds, multiply your weight by 0.36.

How much protein do I need per day by body weight?

The table shows daily grams at three common levels. 0.8 g/kg is the RDA. 1.2 g/kg sits at the top of the range expert groups recommend for healthy older adults. 1.6 g/kg is around the point where extra protein stopped adding muscle in a large analysis of strength-training studies.

Body weight	0.8 g/kg (RDA)	1.2 g/kg	1.6 g/kg
110 lb (50 kg)	40g	60g	80g
130 lb (59 kg)	47g	71g	94g
150 lb (68 kg)	54g	82g	109g
170 lb (77 kg)	62g	93g	123g
190 lb (86 kg)	69g	103g	138g
210 lb (95 kg)	76g	114g	152g
230 lb (104 kg)	83g	125g	167g
250 lb (113 kg)	91g	136g	181g

Calculated from body weight (1 kg = 2.205 lb) and rounded to the nearest gram. These are reference points, not a prescription.

Protein per pound, at a glance

• 0.8 g/kg is about 0.36 g per pound
• 1.2 g/kg is about 0.54 g per pound
• 1.6 g/kg is about 0.73 g per pound
• 2.0 g/kg is about 0.91 g per pound

How much protein do you need to build muscle?

Protein helps build and repair muscle, and resistance training is what tells your body to use it that way. The International Society of Sports Nutrition (ISSN) states that a daily intake of 1.4 to 2.0 g/kg is sufficient for most exercising people who want to build or maintain muscle (Jäger et al., 2017, Journal of the International Society of Sports Nutrition). For a 150-pound person, that's roughly 95 to 136g a day.

A meta-analysis of 49 trials with 1,863 participants looked at protein supplements alongside resistance training. Gains in lean mass stopped increasing once total protein intake passed about 1.62 g/kg a day (Morton et al., 2018, British Journal of Sports Medicine). The same analysis found protein supplements helped less with increasing age and more in people already used to training.

How much protein do older adults need?

Getting enough protein becomes more important as we age. Two expert groups recommend more than the RDA for older adults:

Group	Recommended daily protein	Source
Healthy adults over 65	At least 1.0 to 1.2 g/kg	PROT-AGE (2013)
Older adults who exercise or are active	1.2 g/kg or more	PROT-AGE (2013)
Older adults with acute or chronic illness	1.2 to 1.5 g/kg for most	PROT-AGE (2013), ESPEN (2014)
Severe kidney disease, not on dialysis	May need to limit protein	PROT-AGE (2013)

Sources: Bauer et al., 2013, Journal of the American Medical Directors Association; Deutz et al., 2014, Clinical Nutrition.

Both groups pair protein with exercise. ESPEN recommends daily physical activity, including resistance and aerobic training, for all older people for as long as possible. For more on this, read our guide to protein for older adults.

How much protein do you need during pregnancy?

Needs go up. The US RDA rises to 71g a day during pregnancy and while breastfeeding (National Academies). Your own number depends on your weight, your stage of pregnancy and your health, so ask your doctor, midwife or a registered dietitian. Check with them before adding any protein powder.

How much protein should you eat per meal?

If most of your protein lands at dinner, spreading it out is a simple change. The ISSN's general recommendation is about 0.25 g/kg of a high-quality protein per meal, or 20 to 40g, spaced every 3 to 4 hours across the day (Jäger et al., 2017).

Leucine is part of the reason. It's an essential amino acid that acts as a signal for muscle protein building, and the ISSN suggests each protein dose contain 700 to 3,000 mg of it. Older muscles may need a bigger dose to get the same response: in one analysis, healthy older men needed more protein per meal, relative to their body weight, than young men to reach the maximum muscle-building response (Moore et al., 2015, The Journals of Gerontology: Series A).

A rough plan for someone aiming for 100g a day might look like 30g at breakfast, 30g at lunch, 30g at dinner and a 10 to 20g snack.

Should you get protein from food or powder?

Food first. Eggs, dairy, fish, poultry, meat, beans, lentils, tofu and tempeh all bring other nutrients along with their protein. The ISSN notes that active people can meet their needs through whole foods, and that a supplement is a practical way to add good-quality protein when food alone falls short.

A powder can help on busy mornings, when your appetite is small, or when your diet rules out common protein foods. If you use one, look for a complete protein with all nine essential amino acids, a clear amount of protein per serving, little or no sugar, and published third-party test results. Our guide to the PDCAAS protein quality score explains how protein quality is measured.

Here's where Spacemilk fits. One serving of Spacemilk Complete Protein gives you 20g of complete protein (PDCAAS 1.0), isolated from non-GMO baker's yeast. It has 0g sugar and is free from all 9 major allergens. Our amino acid profile works out to about 1.8g of leucine per 20g of protein. Every batch is third-party tested, with results on our testing page.

Is too much protein bad for you?

For healthy adults, the evidence is reassuring. A meta-analysis of 28 trials with 1,358 adults without kidney disease compared higher-protein diets (at least 1.5 g/kg, 20% of calories, or 100g a day) with normal or lower intakes. It concluded that higher intakes did not adversely affect kidney function, measured as glomerular filtration rate (Devries et al., 2018, The Journal of Nutrition).

Kidney disease is different. People with chronic kidney disease are often advised to limit protein, and the right amount depends on their stage and treatment (Ikizler et al., 2020, KDOQI guideline, American Journal of Kidney Diseases). If you have kidney disease or reduced kidney function, follow your doctor's or renal dietitian's advice before raising your protein.

Who should check with a doctor first?

• You have kidney disease or reduced kidney function, or have been told to limit protein.
• You're pregnant or breastfeeding.
• You have a medical condition or take medications that affect your diet.
• You're planning protein for a child. Ask your pediatrician.
• You have a food allergy, including a known yeast allergy.

This page shares nutrition facts and published guidance, not medical advice.

FAQ

How much protein do I need a day?

The adult RDA is 0.8 g per kilogram of body weight, or about 0.36 g per pound. Active people building muscle often aim for 1.4 to 2.0 g/kg, and healthy adults over 65 at least 1.0 to 1.2 g/kg.

How do I calculate my protein intake?

Divide your weight in pounds by 2.2 to get kilograms, then multiply by your target. A 170-pound person weighs about 77 kg, so 1.2 g/kg is about 93g a day.

Is 100g of protein a day too much?

For many healthy adults, no. It's about 1.6 g/kg for someone who weighs 138 pounds and less per kilogram for heavier people. If you have kidney disease, ask your doctor first.

Can you absorb more than 30g of protein at once?

Your body digests and absorbs the protein you eat. The open question is how much a single meal can put toward muscle building. The ISSN suggests 20 to 40g per meal as a general guide, spread through the day.

Does protein powder count toward my daily total?

Yes. A 20g serving counts the same as 20g of protein from food. For how yeast protein compares with dairy protein, see yeast protein vs whey.

Sources

• National Academies. Dietary Reference Intakes: Recommended Dietary Allowances and Adequate Intakes, Total Water and Macronutrients. NCBI Bookshelf.
• Jäger R, et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. doi:10.1186/s12970-017-0177-8
• 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;52:376–384. doi:10.1136/bjsports-2017-097608
• Bauer J, 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. doi:10.1016/j.jamda.2013.05.021
• Deutz NEP, et al. Protein intake and exercise for optimal muscle function with aging: recommendations from the ESPEN Expert Group. Clin Nutr. 2014;33(6):929–936. doi:10.1016/j.clnu.2014.04.007
• Moore DR, et al. Protein ingestion to stimulate myofibrillar protein synthesis requires greater relative protein intakes in healthy older versus younger men. J Gerontol A Biol Sci Med Sci. 2015. doi:10.1093/gerona/glu103
• Devries MC, et al. Changes in kidney function do not differ between healthy adults consuming higher- compared with lower- or normal-protein diets: a systematic review and meta-analysis. J Nutr. 2018;148:1760–1775. doi:10.1093/jn/nxy197
• Ikizler TA, et al. KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update. Am J Kidney Dis. 2020;76(3 Suppl 1):S1–S107. doi:10.1053/j.ajkd.2020.05.006