Daily Protein Intake Calculator

Protein requirements are set per kilogram of body weight. The calculator uses the same reference values that dietitians and sports scientists use, layered in three steps.

1. Baseline requirement (IOM / WHO). The US Institute of Medicine Dietary Reference Intakes (2005) set the adult Recommended Dietary Allowance at 0.8 g/kg/day— the amount that covers the needs of about 97–98% of healthy sedentary adults. The World Health Organization's safe level of 0.83 g/kg/day corroborates it to within ~4%. Children and teens need more per kilo while growing (1.05 g/kg at ages 1–3, 0.95 at 4–13, 0.85 at 14–18). Pregnancy raises the RDA to 1.1 g/kg and breastfeeding to 1.3 g/kg. This baseline is always shown as your “minimum to meet needs.”
2. Activity and goal range (ISSN 2017). The International Society of Sports Nutrition position stand recommends higher intakes for active people: around 1.2–1.4 g/kg for recreational activity, 1.2–1.6 g/kg for endurance training, and 1.6–2.2 g/kg for resistance training to build or keep muscle (the top end when eating in a calorie deficit). When you pick an active tier, the tool multiplies these factors by your weight to give a low–high target.
3. Per-meal split. Muscle protein synthesis responds best to roughly 0.25–0.55 g/kg of protein per meal (ISSN). The calculator divides your daily target by your number of meals and shows that per-meal window, so you can see whether a single serving is enough or whether the protein needs spreading out.
4. Energy context (AMDR). Each gram of protein supplies 4 kcal. The tool expresses your target as a share of a reference 2,000 kcal diet and plots it against the IOM Acceptable Macronutrient Distribution Range of 10–35% of energy (50–175 g at 2,000 kcal), so you can see if a target is unusually low or high.

Older adults (65+) are handled separately: the 0.8 g/kg RDA is shown as the statutory minimum, but the headline target uses the PROT-AGE / ESPEN expert recommendation of 1.0–1.2 g/kg/day, which better protects against age-related muscle loss. Every factor above is quoted directly from a cited source — no invented multipliers — and pounds are converted to kilograms at the exact 1 lb = 0.45359237 kg before any calculation.

• Institute of Medicine (2005) — Dietary Reference Intakes: Protein and Amino Acids (0.8 g/kg RDA, pregnancy/lactation RDAs, 10–35% AMDR)
• WHO/FAO/UNU (2007) — Protein and Amino Acid Requirements in Human Nutrition, TRS 935 (0.83 g/kg safe level)
• Jäger et al. (2017) — ISSN Position Stand: Protein and Exercise (1.4–2.0 g/kg for active people; 0.25–0.55 g/kg per meal)
• Bauer et al. (2013) — PROT-AGE study group (1.0–1.2 g/kg for adults 65+)
• Medical Research Institute, Ministry of Health Sri Lanka — Food Based Dietary Guidelines (local food protein values)
• USDA FoodData Central — per-portion protein cross-check

The factors on this page were last cross-checked against these sources on 2026-07-10. Protein reference values change rarely; the page is reviewed whenever the IOM DRIs, WHO requirements or ISSN position stand are updated.