Protein intake calculator
The RDA of 0.8 g/kg is the bare minimum to prevent deficiency — not the optimum for your body. Get your real target in 10 seconds, plus what it actually looks like in food.
- Based on peer-reviewed studies (Phillips, Helms, Morton, Bauer)
- Adjusted for your goal, activity & age
- Shown as grams + as real foods
What the 2025–2030 Dietary Guidelines say about protein
The U.S. Dietary Guidelines for Americans, 2025–2030 (HHS and USDA, released January 2026) set a protein serving goal of 1.2–1.6 grams of protein per kilogram of body weight per day, "adjusting as needed based on your individual caloric requirements" (Guidelines, p. 2). For a 70 kg (154 lb) adult, that is 84–112 g of protein per day.
- The 0.8 g/kg RDA is the deficiency floor. The Guidelines' Scientific Foundation report describes the current Recommended Dietary Allowance of 0.8 g/kg/day as "the lowest intake that maintains equilibrium in most healthy adults" that "does not reflect the intake required to maintain optimal muscle mass or metabolic function under all conditions" (Scientific Foundation, p. 37).
- Maintain weight: our range matches the Guidelines. This calculator's maintain-weight range is 1.2–1.6 g/kg/day, the same as the federal 1.2–1.6 g/kg/day goal.
- Lose fat and build muscle: our range goes above the federal goal. The fat-loss and muscle-gain ranges are 1.6–2.2 g/kg/day, which starts at the Guidelines' upper bound. The Scientific Foundation report recommends that people who weight-train aim for an "upper limit of 1.4–1.6 g/kg" (p. 39), and Morton et al. 2018, a meta-analysis of 49 studies, found that protein intake above about 1.6 g/kg/day added no further gains in fat-free mass during resistance training. We show the higher range because Helms et al. 2014, a review for lean, resistance-trained athletes who are dieting, recommends 2.3–3.1 g/kg of lean body mass per day during a calorie deficit. Treat 1.6 g/kg as the point where the evidence for extra muscle gain is strongest and anything above it as optional margin. The Scientific Foundation report notes that no upper limit for dietary protein has been established, "due to a lack of high-quality studies" (p. 38).
- Adults 50 and older: the Guidelines say "equal or greater." They state that some older adults "require equal or greater amounts of key nutrients such as protein" (p. 8) without giving a separate number. The calculator moves adults 50+ to the upper half of each range.
- Body weight basis. The Guidelines say "body weight" without specifying actual or goal weight. This calculator uses the current body weight you enter.
- Kidney disease and other conditions. The Scientific Foundation report found no adverse effects on kidney function "within this tested range" of 1.2–1.6 g/kg in the trials it reviewed (p. 38); those trials were mostly in adults with overweight or obesity during calorie restriction. That does not establish safety for people who already have kidney disease. The Guidelines advise anyone with a chronic disease to talk with a health care professional about adapting them (p. 9). If you have chronic kidney disease, check your protein target with your clinician before using any number on this page.
Sources: Dietary Guidelines for Americans, 2025–2030 and The Scientific Foundation for the Dietary Guidelines for Americans, 2025–2030; page numbers are the printed page numbers. Our side-by-side comparison is on the methodology page. What the Guidelines' daily servings add up to in grams of protein is on our inverted food pyramid page.
How this calculator works
We use the Mifflin-St Jeor equation to estimate your Total Daily Energy Expenditure (TDEE), then apply a goal-specific protein coefficient based on the latest sports nutrition research:
- Maintain weight: 1.2–1.6 g/kg of bodyweight (Phillips & Van Loon 2011)
- Lose fat: 1.6–2.2 g/kg — preserves lean mass under deficit (Helms et al. 2014)
- Build muscle: 1.6–2.2 g/kg — meta-analysis ceiling (Morton et al. 2018)
Adults 50+ are biased toward the upper end of each range to combat anabolic resistance (Bauer et al. 2013). For the full math and citations, see the methodology page →
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