The three published answers
- 0.8 g per kg per day: the RDA. The National Academies of Sciences, Engineering, and Medicine set the adult RDA at 0.8 g per kg of body weight, about 56 g a day for the reference adult in their materials (National Academies presentation).
- 1.2–1.6 g per kg per day: Dietary Guidelines for Americans 2025–2030. The guidelines list a protein serving goal of 1.2–1.6 g per kg per day, adjusted to your calorie needs (DGA 2025–2030, PDF). It is a US dietary guideline.
- 1.4–2.0 g per kg per day: ISSN position stand. For building and maintaining muscle, the International Society of Sports Nutrition says this range is sufficient for most exercising individuals (Protein and exercise, 2017).
What that works out to
| Body weight | RDA (0.8 g/kg) | DGA 2025–2030 (1.2–1.6) | ISSN (1.4–2.0) |
|---|---|---|---|
| 60 kg (132 lb) | 48 g | 72–96 g | 84–120 g |
| 75 kg (165 lb) | 60 g | 90–120 g | 105–150 g |
| 90 kg (198 lb) | 72 g | 108–144 g | 126–180 g |
What it costs
At the cheapest product in our data (Grade A Large White Eggs, Kroger.com), 100 g of protein costs $1.65. For a 75 kg adult that is $0.99 a day at the RDA and $1.73–$2.47 a day at the ISSN range, protein only. Try your own numbers in the calculator.
Cautions
These are general reference ranges, not medical advice. If you have kidney disease or another condition, or you are pregnant, ask a doctor or registered dietitian before changing how much protein you eat.