How this number is calculated
The evidence-based range for building or keeping muscle is 0.7–1.0 grams of protein per pound of target body weight per day. This calculator anchors on your goal weightwhen you give one, because your muscle mass — not your fat mass — sets the requirement. If you're losing fat it pushes toward the high end, since protein is what tells your body to burn fat instead of muscle in a deficit.
It's a starting point, not a lab result. Bodyweight-based targets are what the research actually supports for most lifters, and they beat any precise-looking formula that pretends to know your exact lean mass. Want the reasoning in full? Read how much protein you actually need — including where the marketing exaggerates.