The baseline Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of bodyweight daily. Harvard Health notes this figure was set to prevent deficiency in a sedentary adult — not to serve as a target for someone building or maintaining muscle through regular training.
The range that actually matters for lifters
Mayo Clinic Health System puts the target for people who regularly lift weights or train for endurance between 1.2 and 1.7 grams of protein per kilogram of bodyweight daily. Harvard Health's cited research echoes a similar range for older adults working to preserve muscle mass, around 1 to 1.6 grams per kilogram. That's meaningfully higher than the baseline RDA, but well short of the extreme figures often circulated in bodybuilding culture.
For an 80 kg (176 lb) lifter training regularly, that works out to roughly 96 to 136 grams of protein daily — not 250 or beyond. The calculators page on this site uses 2 grams per kilogram as a moderately generous figure that covers this whole range without requiring precise tracking.
Is more protein ever better?
Rarely, and higher intake has its own tradeoffs. Harvard Health cautions against very high intakes sustained long-term — 2 grams per kilogram or beyond — since evidence for further benefit past that point is weak. Mayo Clinic Health System adds that excess protein tends to be used for energy or stored rather than turned into muscle. The training stimulus itself is still the primary driver of muscle growth (see progressive overload). Protein supplies material to repair and build from that stimulus — it doesn't replace it.
Where should the protein come from?
Both sources point to whole-food protein as the priority — lean meats, fish, eggs, dairy, legumes, and tofu — with powders as a convenient supplement, not a substitute.
The takeaway
A reasonable target for anyone training regularly is around 1.2–1.7 grams of protein per kilogram of bodyweight. The calculator's 2g/kg figure sits deliberately at the generous end of that range so precise tracking isn't necessary. Past that point, extra protein appears to add little — training and recovery matter far more.