Protein Calculator

How much protein do I need a day?

The baseline RDA is about 0.8g per kg of bodyweight, which covers minimum needs for a sedentary adult but is generally considered too low for anyone exercising regularly. This calculator scales the target up based on your goal — general fitness, weight loss, muscle gain, or athletic performance — using the ranges in the International Society of Sports Nutrition (ISSN) and American College of Sports Medicine (ACSM) position statements.

Those two bodies put the useful range for active people at 1.4–2.0 g/kg (ISSN) and 1.2–2.0 g/kg (ACSM). Every goal on this page stays inside them, so the top of any range is 2.0 g/kg. In pounds, the RDA works out to about 0.36 g per lb and 2.0 g/kg to about 0.9 g per lb. For a 154 lb (70 kg) adult, that's 56 g a day at the RDA and up to 140 g at the top of the active range.

Protein by body weight

Daily grams for common body weights, computed with the same g/kg figures the calculator uses. The middle column fits general fitness; the right column covers weight loss, muscle gain and the top of the athletic range.

These figures assume an ordinary body composition. If you carry a lot of body fat, multiplying your full weight overstates what muscle needs, so it's common to use a goal weight or lean body weight instead. A tape-measure estimate from the body fat calculator gives you a lean-mass figure to work from.

Protein for weight loss

Higher protein intake during a calorie deficit — roughly 1.6-2.0g/kg — helps preserve lean muscle mass while you lose fat, and protein tends to be more filling than carbs or fat per calorie, which can help manage hunger. This calculator's "Weight loss" goal targets 1.8g/kg, the middle of that range.

Protein still counts toward your calories, at 4 per gram. A 126 g target is about 500 calories, so set your total first with the calorie calculator and fit protein inside it.

Protein for muscle gain

The ISSN position stand puts 1.4–2.0 g/kg a day as enough for most exercising people to build and maintain muscle, and ACSM's range for athletes tops out at the same 2.0 g/kg. This calculator's "Muscle gain" goal targets 2.0g/kg with a range from 1.6 — resistance training and total calorie intake still matter as much as hitting this number precisely.

"Athletic performance" uses the full ISSN band, 1.4–2.0 g/kg, with the headline set at 2.0 for people training hard most days. Endurance athletes in lighter training can sit nearer the bottom of that band.

How to split protein across meals

How you spread protein matters less than the daily total, but the ISSN suggests about 0.25 g per kg of body weight per meal, or roughly 20–40 g, every 3–4 hours. For a 70 kg person, 0.25 g/kg comes to about 18 g per meal. The calculator shows your target divided over four meals as a practical split: three meals and a snack, or four smaller meals, both work.

Protein in common foods

Grams of protein per typical serving, from USDA FoodData Central. Brands and cooking methods vary, so check labels for packaged foods.

Weights are for cooked food unless noted; 3 oz of raw chicken cooks down to less. If you weigh food in grams, the kg to lbs converter helps when a label or recipe uses the other system.

Older adults and pregnancy

Needs change in some life stages, and this calculator's goals don't model them directly:

• Adults over 65. The PROT-AGE study group (Bauer et al., 2013) recommends at least 1.0–1.2 g/kg a day to help maintain muscle and function, 1.2 g/kg or more for those who exercise, and 1.2–1.5 g/kg for most older adults with acute or chronic illness. Older adults with severe kidney disease who aren't on dialysis are an exception and may need less.
• Pregnancy. The US Dietary Reference Intakes set the protein RDA at 1.1 g/kg a day (about 71 g) for the second half of pregnancy, up from 0.8 g/kg. Your prenatal care team can tailor that to you.

How this calculator works

Daily protein target (g) = bodyweight (kg) × a goal-specific multiplier, ranging from 0.8 for sedentary adults up to 2.0 for muscle gain and athletic performance. Each goal also has a low and high end, shown as the range. Protein provides 4 calories per gram, so this calculator also shows how much of your daily calorie budget that target represents.

Sources

The formulas on this page come from the published research below. Last updated October 11, 2026. This calculator gives estimates for general information. It isn't medical advice, so check anything important with a qualified professional.

1. Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: The National Academies Press; 2005.Used for: 0.8 g/kg/day RDA for sedentary adults, and 1.1 g/kg in the second half of pregnancy
2. Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20.Used for: 1.4–2.0 g/kg/day ranges for active people
3. Thomas DT, Erdman KA, Burke LM. American College of Sports Medicine Joint Position Statement: Nutrition and Athletic Performance. Med Sci Sports Exerc. 2016;48(3):543–568.Used for: 1.2–2.0 g/kg/day for athletes, higher during energy restriction
4. Bauer J, Biolo G, Cederholm T, 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(8):542–559.Used for: 1.0–1.2 g/kg/day for adults over 65
5. U.S. Department of Agriculture, Agricultural Research Service. FoodData Central (SR Legacy).Used for: Protein content of the common foods in the table