Protein Needs Calculator
Calculate a daily protein target in grams from body weight, activity and goal, from 0.8 to 2.0 g per kg, split across four meals.
Note: Protein needs vary based on individual factors. These recommendations are general guidelines. People with kidney disease, and anyone who is pregnant or managing a medical condition, should ask a doctor or registered dietitian before raising protein intake.
Updated Formula covered by automated tests
Protein recommendations are almost always expressed per kilogram of body weight, which makes them awkward to use if you think in pounds and meals. This calculator does the conversion: enter your weight, how active you are and whether you want to maintain, lose or build, and it returns a daily protein target in grams, the rate per kilogram behind it, and what that looks like split across four meals.
The lowest setting is the Recommended Dietary Allowance of 0.8 g per kg, the amount that covers the needs of nearly all healthy, inactive adults. The higher settings step up toward 2.0 g per kg, the top of the range sports nutrition bodies give for people in regular hard training or trying to keep muscle while losing fat.
The formula
- weight
- Current body weight; pounds are converted with the exact international factor
- rate
- Grams of protein per kilogram per day, from 0.8 (sedentary, maintaining) to 2.0 (athlete, building muscle)
- 4
- Number of protein-containing meals or snacks the daily total is divided into
The 0.8 g/kg allowance comes from the US National Academies’ Dietary Reference Intakes, based on nitrogen balance studies that measure how much protein adults need to replace what they break down each day. It is set two standard deviations above the average requirement, so it is generous for the typical sedentary adult rather than a bare minimum.
For athletes, the 2016 joint position statement 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 per day, with the upper end useful during calorie restriction to help preserve lean mass. The calculator’s grid of activity levels and goals is a simple way of picking a point in that range; it is a preset, not a clinical prescription.
Worked example
Elena weighs 165 lb, lifts weights four days a week and wants to build muscle. She chooses Active and Build Muscle, which uses 1.6 g per kg.
- 1 Convert weight: 165 × 0.45359237 = 74.84 kg.
- 2 Multiply by the rate: 74.84 × 1.6 = 119.7 g, which rounds to 120 g per day.
- 3 Split across four meals: 119.7 ÷ 4 = 29.9 g, about 30 g each.
- 4 Compare with the RDA: 74.84 × 0.8 = 59.9 g, so her target is double the baseline allowance.
Result: Elena’s daily protein target is about 120 g, roughly 30 g at each of four meals. That could be eggs at breakfast, a chicken salad at lunch, Greek yogurt as a snack and fish at dinner.
Before you rely on the result
- The activity and goal grid is a simplification; real needs depend on training type, age, total calorie intake and health status.
- Older adults, pregnant or breastfeeding women and people recovering from surgery or illness can have higher needs, while people with kidney or liver disease may need lower targets set by a clinician.
- Supplements are not required to reach these numbers, and the calculator does not assess the quality or safety of any product.
Frequently asked questions
Should I use my current weight or my goal weight?
For most people current weight is fine. If you are carrying a lot of extra body fat, a per-kilogram rate based on current weight can give a very high number; using a goal or adjusted weight is a common workaround that a dietitian can help you choose.
Can eating too much protein harm my kidneys?
In healthy adults, intakes up to around 2 g/kg have not been shown to damage the kidneys. People who already have chronic kidney disease are usually advised to limit protein, so they should follow their nephrologist’s or dietitian’s target rather than this calculator.
Why split protein across four meals?
Muscle building responds to repeated doses through the day, and many sports nutrition studies have used servings of roughly 20 to 40 g. Four meals is a practical pattern, but the daily total matters most; three larger meals work too.
Do plant-based eaters need more protein?
Plant proteins are often a little less digestible and lower in one or more essential amino acids, so some dietitians suggest aiming slightly higher or combining sources such as legumes and grains. Soy, lentils, tofu, tempeh and seitan are all substantial sources.
Sources
- Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance (2016) (pubmed.ncbi.nlm.nih.gov)
- National Academies: Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (nap.nationalacademies.org)