Protein Calculator — How Much Protein Do You Need a Day?

How this calculator works

Protein needs scale with body weight and activity level — people doing regular strength training or intense exercise need substantially more than sedentary individuals.

Protein (g) = weight (kg) × factor — Sedentary ≈ 0.8–1.0 g/kg · Adults 65+ ≈ 1.0–1.2 g/kg · Moderately active ≈ 1.2–1.6 g/kg · Athletes ≈ 1.6–2.2 g/kg · Pregnancy (2nd–3rd trimester) 1.1 g/kg

For comparison, the Dietary Guidelines for Americans, 2025–2030 set a general protein goal of 1.2–1.6 g per kg of body weight a day — above the 0.8 g/kg RDA, which is the minimum to prevent deficiency rather than a target.

By Suhaib Hassan · Reviewed 28 September 2026 against the sources below · How CalculatePilot verifies formulas →

Protein timing and distribution

Beyond total daily amount, how protein is distributed across meals may matter for muscle protein synthesis — many guidelines suggest spreading intake across 3-4 meals with 20-40g of protein each (roughly 0.4 g per kg of body weight per meal), rather than consuming it all in one large meal.

Protein needs also typically increase during periods of calorie restriction (dieting) to help preserve muscle mass, which is why the higher end of activity-based ranges is often recommended during active fat-loss phases.

A worked example

An 82kg moderately active person: protein range is 82 times 1.2 to 82 times 1.6, or roughly 98-131g per day.

The same person training seriously as an athlete would see a range of 82 times 1.6 to 82 times 2.2, or roughly 131-180g per day — nearly 50g/day higher at the top end than the moderately active estimate.

Protein quality

Complete protein sources containing all essential amino acids (found in most animal products, soy, and some plant combinations like rice and beans) are generally considered more effective for muscle maintenance than incomplete sources alone. Medical information, not medical advice: people with kidney disease should follow their doctor's protein guidance.

Sources

• Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. 2005 (RDA 0.8 g/kg; 1.1 g/kg in pregnancy).
• Jäger R, et al. International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr 2017;14:20.
• 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. Br J Sports Med 2018;52:376–384.
• 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;14:542–559.
• Schoenfeld BJ, Aragon AA. How much protein can the body use in a single meal for muscle-building? J Int Soc Sports Nutr 2018;15:10.
• Dietary Guidelines for Americans, 2025–2030 (protein goal 1.2–1.6 g/kg/day)
• USDA FoodData Central (food protein values)

Read the guide: How much protein do you need per day? Chart by weight

Frequently asked questions

Can eating too much protein be harmful?expand_more

For most healthy people, higher protein intakes within these ranges are considered safe, though people with certain kidney conditions should consult a doctor about appropriate protein levels.

Does this factor in muscle-building goals?expand_more

The athlete/strength training range already reflects typical recommendations for building or maintaining muscle mass during resistance training.

Do I need protein supplements to hit my target?expand_more

Not necessarily — whole foods like meat, fish, eggs, dairy, and legumes can meet most people's protein needs, though supplements like whey protein can be a convenient way to fill gaps.

Is it better to spread protein throughout the day?expand_more

Many nutrition guidelines suggest distributing protein across 3-4 meals rather than one large serving, since the body can only use a limited amount for muscle synthesis at a time.

Do older adults need more protein?expand_more

Often, yes. The PROT-AGE Study Group recommends 1.0–1.2 g per kg of body weight a day for healthy adults over 65 — more than the 0.8 g/kg RDA — to help maintain muscle.