Protein calculator

Protein is set in grams per kilogram of body weight per day and rounded to whole grams, as Pendum Macros does. Imperial inputs are converted exactly (1 lb = 0.45359237 kg) first. Each goal uses a published range, and its target is one of the protein settings Pendum Macros offers (1.4, 1.6, 2.0 or 2.2 g/kg).

protein (g) = round(weight × g/kg)

lean mass = weight × (1 − fat % / 100)
deficit: 2.3–3.1 g per kg lean mass
  (shown when 3.1 × lean mass > target)

Maintain. The International Society of Sports Nutrition puts 1.4 to 2.0 g/kg a day as enough for most people who exercise. The target is 1.6 g/kg: in a meta-analysis of 49 trials, Morton and colleagues found no further average gain in lean mass from protein beyond about 1.6 g/kg.

Build muscle. The same meta-analysis placed that point at 1.62 g/kg, with a 95% confidence interval of 1.03 to 2.20 g/kg, so the authors suggest about 2.2 g/kg for people seeking the most lean mass from resistance training. Schoenfeld and Aragon use the same 1.6 to 2.2 g/kg range. The target is 2.0 g/kg, the setting nearest the middle of that range.

Lose fat. In a calorie deficit, recommendations for athletes run from 1.6 to 2.4 g/kg (Hector and Phillips). Needs rise with a bigger deficit and with leanness, so the target is 2.2 g/kg. A review of lean, resistance-trained athletes in a deficit found 2.3 to 3.1 g per kg of lean mass (Helms and colleagues). Enter a body-fat percentage to see that range in grams; it is shown when its top is above the target, which is the case below about 29% body fat.

High body fat. Every range here is per kg of total body weight. When the target comes to more than 3.1 g per kg of lean mass, the top of the Helms range, the result says so. That happens past about 29% body fat for Lose fat, 35% for Build muscle and 48% for Maintain. In that case, base the number on a goal weight.

Per meal. About 0.4 g/kg a meal over four or more meals reaches 1.6 g/kg a day (Schoenfeld and Aragon). The table divides the daily target evenly across 3, 4 and 5 meals.

RDA. The recommended dietary allowance for adults is 0.8 g/kg a day. It is set to prevent deficiency in nearly all healthy adults, not to support training, so it appears as a floor for comparison.