TL;DR
- For building muscle, the research converges on 1.6-2.2g of protein per kg of body weight per day — roughly 0.7-1.0g per pound.
- A large meta-analysis found benefits plateaued around 1.6g/kg, with the upper end of the range acting as insurance rather than extra gains.
- For a 180lb (82kg) lifter that's 130-180g daily. For 140lb (64kg), 100-140g.
- Distribution matters: 25-40g per feeding across 4-5 meals beats the same total in two large hits.
- Protein is necessary but not sufficient — without progressive resistance training and adequate calories, extra protein doesn't become muscle.
"How much protein do I need to build muscle" is the most-asked question in gym nutrition, and the answer has actually settled over the past decade. 1.6-2.2g per kilogram of body weight daily covers essentially everyone training for hypertrophy, and the evidence for that range is strong. What's less well understood is where the number comes from, why the top of the range exists at all, and what happens on either side of it. This guide gives you the number, the reasoning, and the practical version.
The number, and where it comes from
1.6g/kg is the point of diminishing returns
The most influential work here is a 2018 meta-analysis by Morton and colleagues covering 49 studies and roughly 1,900 participants. It found that protein intake beyond approximately 1.6g/kg per day produced no further gains in lean mass in resistance-trained individuals. That's the strongest single anchor for the recommendation.
The confidence interval extended up toward 2.2g/kg, which is why the recommended range has an upper bound rather than a hard stop. Going to 2.2 isn't wasteful exactly — it's insurance against measurement error, under-reporting, and individual variation.
Why the RDA is irrelevant here
The RDA of 0.8g/kg is the amount required to prevent deficiency in a sedentary adult — a floor for avoiding harm, not a target for building tissue. Using it as a muscle-building goal is a category error, and it's roughly half of what the hypertrophy literature supports.
Your number
| Body weight | 1.6g/kg (floor) | 2.0g/kg (solid target) | 2.2g/kg (upper) |
|---|---|---|---|
| 130 lb / 59 kg | 94g | 118g | 130g |
| 150 lb / 68 kg | 109g | 136g | 150g |
| 170 lb / 77 kg | 123g | 154g | 170g |
| 190 lb / 86 kg | 138g | 172g | 190g |
| 210 lb / 95 kg | 152g | 190g | 209g |
| 230 lb / 104 kg | 166g | 208g | 229g |
A useful shortcut: 1 gram per pound of body weight lands near the top of the range and is easy to remember. It's slightly more than most people need, which is a reasonable place to err.
If you carry significant body fat
Protein requirements track lean mass more closely than total mass, so at higher body-fat levels, scaling off total body weight inflates the target. Using goal weight or lean body mass gives a more sensible number — a 300lb individual doesn't need 300g of protein.
Distribution: the part people skip
25-40g per feeding, 4-5 times daily
Muscle protein synthesis responds per meal, and each feeding produces a discrete response. Spreading intake across four or five feedings stimulates that response more times per day than cramming the same total into two meals.
The practical failure point is almost always breakfast — typical breakfast foods deliver 5-12g. Fixing that one meal often closes half the gap on its own. See our high protein breakfast guide.
What protein alone won't do
• Without progressive resistance training, surplus protein is oxidised for energy or stored — it doesn't spontaneously become muscle. The training provides the signal; protein provides the material.
• Without adequate calories, muscle gain is slow at best. Building tissue in a deficit is possible in specific circumstances but much harder — covered in can you build muscle in a calorie deficit.
• Beyond roughly 2.2g/kg, more protein doesn't produce more muscle in the available research. It isn't dangerous for healthy people — just expensive.
FAQ
How much protein do I need to build muscle?
1.6-2.2g per kg of body weight daily (roughly 0.7-1.0g per pound). Meta-analysis suggests gains plateau near 1.6g/kg, with the upper end serving as insurance.
Is 1g per pound of body weight necessary?
Not strictly — it sits at the top of the evidence-supported range. It's a fine target because it's easy to remember and errs on the generous side, but 0.7-0.8g/lb is sufficient for most people.
Can I build muscle on less protein?
Yes, particularly if you're new to training — beginners gain muscle across a wide range of intakes. But you'll be leaving results on the table below roughly 1.6g/kg, and the gap widens as you become more trained.
Does protein timing matter for building muscle?
Far less than total daily intake. Distribution across 4-5 feedings offers a modest advantage over 1-2, but the "anabolic window" is much wider than it was once presented — see whey protein before or after a workout.
The Bottom Line
1.6-2.2g per kg of body weight daily. Gains plateau near 1.6g/kg in the best available meta-analysis; the top of the range is insurance, not extra muscle.
Spread it across 4-5 feedings of 25-40g. Breakfast is where most people lose 20-30g without noticing.
Scale off lean mass or goal weight if you carry significant body fat — requirements track lean tissue, not total weight.
Protein is the material, training is the signal. Neither builds muscle without the other.
Further Reading
How Much Protein Can Your Body Use in One Meal?
How to Eat 150 Grams of Protein Per Day
