You multiply your body weight by one. That's the target: one gram of protein per pound, every day. You've tracked it on your phone after meals, added a shake before bed to close the gap, picked the higher-protein option at lunch because the number still needs work.
One gram per pound converts to 2.2 grams per kilogram. The research ceiling for muscle gains sits at 1.62, and your daily goal is 36% above where additional protein stops mattering.
Is 1g of Protein Per Pound of Body Weight Too Much?
Gains from protein stop at about 0.73 g per pound (1.62 g/kg per day), based on 49 controlled trials and 1,863 lifters. At 1 g per pound, the standard gym target overshoots that ceiling by 36%. The excess isn't harmful. It just stops producing additional muscle.
— Morton et al. 2018 · British Journal of Sports Medicine · n=1,863
That ceiling came from 49 controlled trials on protein and muscle growth. The gains flatlined at 1.62 grams per kilogram per day. The true number could sit anywhere between 1.0 and 2.2, so at the most generous reading, your 1-per-pound target just barely touches the ceiling instead of clearing it by a third.
Lifters ate 4.4 g/kg per day, more than twice your target, for eight straight weeks. No fat gain. No extra muscle either. Every gram above the ceiling bought nothing extra. The excess is safe. It's also pointless for building.
Your body doesn't throw any of it away. A large protein meal keeps the building machinery running for over 12 hours, and the protein gets used for repair, replacement, immune function. Your body uses every gram. It just stops building more muscle past a point, and that point is lower than the target you've been chasing.
The number you need depends on the situation you're in, not on a formula the gym inherited. If you're maintaining or building, the ceiling is ~1.6 g/kg (about 0.73 g per pound). If you're cutting, the deficit raises it to 2.3–3.1 g/kg (roughly 1.0–1.4 g per pound) because protein shifts from building to defending lean mass. Over 60, it drops to 1.2–1.6 g/kg — the overshoot from 1 g per pound gets even larger.
Your body uses every gram. It just stops building more muscle past a point, and that point is lower than the target you've been chasing.
Training itself accounts for roughly 91% of your gains from a resistance program. Protein supplementation covers the remaining 9%. The number you've been tracking, multiplying, and closing the gap on every night controls the smaller slice of the equation.
The thing building your muscle was never the number on your phone. How much protein you actually need depends on where your body is right now, and the answer has never been one number.