Protein Calculator

For most people who exercise regularly, the International Society of Sports Nutrition puts the useful range at 1.4-2.0 grams per kilogram of body weight per day for building and maintaining muscle. That is well above the general-population RDA (0.8 g/kg), which is set to prevent deficiency, not to support training.

Yes, and this is the part most generic calculators miss. In a calorie deficit, your body is more prone to breaking down muscle for energy, so protein needs rise rather than fall. The research on contest-prep bodybuilders found 2.3-3.1 grams per kilogram of lean body mass preserved muscle best during aggressive cutting phases. Translated to total body weight for someone at a moderate body fat percentage, that works out to roughly 1.8-2.4 g/kg, which is the range this calculator uses for a fat loss goal.

Not meaningfully past a point. Intakes above roughly 2.2-2.4 g/kg show diminishing returns for muscle retention or growth in most people, and a few studies on very high intakes (above 3.0 g/kg) found possible body-composition benefits but on thinner evidence. There is no strong reason to chase numbers well above this calculator's range unless you have a specific reason to.

The ISSN position stand also recommends spreading protein across the day rather than loading it into one meal: roughly 0.25 g/kg (commonly 20-40g) per serving, spaced every 3-4 hours, each containing a good mix of essential amino acids. Hitting your daily number in two meals is less effective for muscle protein synthesis than spreading it across four.