Protein Intake Calculator

Why protein needs vary so much

Government dietary guidelines often quote a minimum protein intake of around 0.8 grams per kilogram of body weight, but that figure was set to prevent deficiency in sedentary people — not to support athletic performance or muscle growth. Research on resistance training and muscle protein synthesis consistently shows that active people, and especially those trying to build or preserve muscle, benefit from noticeably higher intakes. This calculator adjusts your target based on your activity level and goal rather than giving everyone the same baseline number.

How the targets are set

For a sedentary lifestyle we use a baseline closer to the standard guideline, for general activity we move toward 1.2 g/kg, for muscle-building goals we move toward 1.8 g/kg, and for serious athletes we push toward roughly 2.1 g/kg. These figures sit within the ranges commonly cited in sports nutrition research and by professional bodies such as the International Society of Sports Nutrition, which generally supports intakes of 1.4–2.2 g/kg for people engaged in regular resistance or endurance training.

Spreading protein through the day

Research suggests that spreading protein across three to five meals, with roughly 20–40 grams per meal, supports muscle protein synthesis more effectively than eating the bulk of it in one sitting. This matters more for people specifically training for muscle growth than for someone simply eating for general health, but it's a useful habit either way since it also tends to support fullness throughout the day.

Where the numbers can flex

Body weight alone is a reasonable starting point, but very lean, muscular individuals may benefit from calculating protein needs based on lean body mass instead, since fat tissue doesn't require the same protein support as muscle. If you're carrying a higher body fat percentage, using our Body Fat Calculator first to estimate lean mass can give you a more tailored number than using total body weight alone.