Protein Intake by Bodyweight Calculator
Daily protein needs are usually expressed per kilogram of bodyweight. The official U.S. Recommended Dietary Allowance is 0.8 grams per kilogram per day for healthy adults, a floor that prevents deficiency in nearly everyone. Athletes, people in a calorie deficit, and many older adults often target more, but those higher figures are individual and should come from a qualified professional. This calculator multiplies your bodyweight by the grams-per-kilogram target you choose, converts pounds to kilograms when needed, and shows the official RDA amount alongside your target for reference.
Protein intake formula
Bodyweight in kg = pounds / 2.20462 (if entered in pounds)
Daily protein = bodyweight in kg * target g per kg
RDA amount = bodyweight in kg * 0.8
Per meal = daily protein / 4
The 0.8 g/kg RDA is the official adequacy floor for healthy adults from the National Academies Dietary Reference Intakes. Higher targets reflect athletic or clinical guidance and should be set with a professional.
Protein context
- The RDA for protein is 0.8 g/kg/day for healthy adults (National Academies DRI).
- The Acceptable Macronutrient Distribution Range for protein is 10 to 35% of total calories.
- Spreading protein across meals can support muscle protein synthesis better than one large dose.
- Older adults and athletes often target higher intakes; confirm with a registered dietitian.
- This tool reports a target only and is not a substitute for medical or dietary advice.
Protein intake: frequently asked questions
How much protein do I need per day?
The Recommended Dietary Allowance set by the U.S. National Academies is 0.8 grams of protein per kilogram of bodyweight per day for healthy adults. This is the amount that meets the needs of nearly all healthy people; it is a floor for adequacy, not an optimum for athletes or older adults, who often target higher intakes.
How does this calculator work?
It multiplies your bodyweight in kilograms by the grams-per-kilogram target you select. If you enter weight in pounds, it converts to kilograms first by dividing by 2.20462. The default target of 0.8 g/kg matches the RDA; you can raise it to reflect athletic or clinical guidance from a qualified professional.
Why are athletic protein targets higher than the RDA?
The RDA is set to prevent deficiency in the general population. People doing heavy resistance or endurance training, those losing weight, and many older adults may benefit from more protein to support muscle. Because those higher targets are individual and depend on training and health, this calculator leaves the target as an editable input rather than assuming one.
Should I use total bodyweight or lean mass?
The RDA is expressed per kilogram of total bodyweight, so this calculator uses total bodyweight by default. Some practitioners base targets on lean body mass instead, especially at higher body-fat levels. If your guidance uses lean mass, enter that figure as your weight.
Can I eat too much protein?
Very high intakes are generally safe for healthy people, but people with kidney disease or other conditions should follow medical advice. This tool reports a target intake only; it is not medical or dietary advice. Consult a registered dietitian or physician for personalized guidance.
Official sources
- National Academies of Sciences, Engineering, and Medicine: Dietary Reference Intakes.
- Academy of Nutrition and Dietetics: protein and nutrition guidance.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.