Daily Protein Intake Calculator

Calculator

How we calculate it

The recommended dietary allowance for protein set by the Institute of Medicine is 0.8 grams per kilogram of body weight per day for adults aged 19 and over. It is important to read that figure correctly: an RDA is the intake estimated to meet the requirement of 97.5% of healthy people, which makes it a floor for adequacy rather than an optimum. Several professional groups recommend more in specific circumstances. The PROT-AGE Study Group and ESPEN recommend 1.0 to 1.2 g/kg a day for healthy adults aged 65 and over, to help maintain muscle mass. The joint position of the Academy of Nutrition and Dietetics, Dietitians of Canada and the American College of Sports Medicine gives a range of 1.2 to 2.0 g/kg a day for people training regularly. This calculator shows the RDA always, and adds those ranges when the age or training answers make them relevant — as ranges, because researchers genuinely disagree about where within them most people should sit. If a daily calorie figure is entered, the acceptable macronutrient distribution range for protein, 10 to 35% of energy, is also expressed in grams at 4 kcal per gram. Grams here are calculated from total body weight; some references use ideal or lean body weight instead, which gives a lower figure at higher body weights.

Important limitations

• The 0.8 g/kg RDA is a floor for adequacy, not an optimum. It is the intake estimated to meet the needs of 97.5% of healthy adults, and was never intended as the amount producing the best outcome for muscle, aging or recovery.
• Published recommendations above the RDA are ranges, and researchers disagree about where within them most people should sit. The calculator shows the ranges rather than choosing a point inside them.
• Grams per kilogram is calculated here from total body weight. Some references use ideal or lean body weight instead, which gives a noticeably lower figure at higher body weights.
• Requirements are higher in pregnancy and breastfeeding, during recovery from surgery, burns or serious illness, and separate reference values apply to children and adolescents.
• Protein intake needs to be limited and clinically supervised in some conditions, notably advanced chronic kidney disease and certain inherited metabolic disorders, where a general figure could be unhelpful.
• Total daily grams say nothing about protein quality, amino acid profile, or how intake is spread across the day, all of which the research suggests matter.
• These are general educational estimates rather than a nutrition plan, and they are not appropriate as a target if you have or are recovering from an eating disorder.