Protein Calculator: Daily Protein Intake in Grams
Work out how many grams of protein to eat a day, from your calorie target and by body weight: the 0.8 g/kg RDA and 1.2 to 2.0 g/kg for active people, with the AMDR range. Nothing is sent anywhere.
Enter a calorie target, or your details, to see your macros.
About the Protein Calculator
The Protein Calculator works out how many grams of protein to eat a day in two ways. The first starts from your calorie target and the share of calories you want from protein. The second starts from your body weight: the Recommended Dietary Allowance (RDA) of 0.8 g per kilogram for healthy adults, and the 1.2 to 2.0 g per kilogram range recommended for people who train regularly. The calculator also shows the protein part of the Acceptable Macronutrient Distribution Range (AMDR), 10 to 35 percent of calories, in grams.
Type a daily calorie target and your weight in kilograms or pounds, or estimate the target from your age, sex, height, weight, activity level and goal. Nothing is uploaded; the figures are worked out in your browser and never leave your device.
This is an estimate, not medical advice. People with kidney disease, and anyone told to limit protein, should follow their doctor's advice rather than these figures.
The two ways to set protein
By body weight
The RDA is set at 0.8 g of good-quality protein per kilogram of body weight a day, enough for nearly all healthy adults who are not especially active. For a 70 kg adult that is 70 × 0.8 = 56 g. The joint position statement of the American College of Sports Medicine, the Academy of Nutrition and Dietetics and Dietitians of Canada recommends 1.2 to 2.0 g per kilogram for athletes, which gives 84 to 140 g for the same person.
By share of calories
At 4 kcal per gram, protein grams are the calorie target times the protein share, divided by 4. At 2,000 kcal and 20 percent, that is 2,000 × 0.20 ÷ 4 = 100 g. The AMDR of 10 to 35 percent gives 50 to 175 g at 2,000 kcal.
Which figure to use
The RDA is a minimum to avoid deficiency, not a target for building muscle. If you strength train or do endurance sport, aim for somewhere in the 1.2 to 2.0 g per kilogram range, spread over the day's meals. If you are losing weight, protein near the top of that range helps keep lean mass. When the two methods disagree, the body weight figure is usually the better guide, and the calorie share can then be adjusted to match.
Older adults may benefit from more than the RDA, and needs rise in pregnancy and while breastfeeding. A registered dietitian can set a figure for your situation.
Related tools
The full Macro Calculator shows carbohydrate and fat alongside protein, and the Calorie Calculator explains the calorie estimate. Convert your weight from pounds with the Mass Converter, or check where it sits with the BMI Calculator.
Sources
- Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. National Academies Press, 2005 (the protein RDA and AMDR).
- Thomas DT, Erdman KA, Burke LM. American College of Sports Medicine Joint Position Statement. Nutrition and Athletic Performance. Medicine & Science in Sports & Exercise 2016;48(3):543–568.
Open-source credits
The calculations are implemented in-house in TypeScript, with no third-party libraries. They follow the Institute of Medicine RDA of 0.8 g per kilogram and AMDR, the 1.2 to 2.0 g per kilogram range of the 2016 ACSM joint position statement and the Atwater factor of 4 kcal per gram.