Most people need 1.2 to 1.6 grams of protein per kilogram of body weight per day to build muscle effectively. For a 180-pound (82 kg) person, that works out to roughly 100 to 130 grams of protein daily. Going above 1.6 g/kg/day shows diminishing returns for most people, though certain situations call for more.
That range assumes you’re doing regular resistance training. Without the training stimulus, extra protein alone won’t build meaningful muscle. The two work together, and getting the balance right matters more than simply eating as much protein as possible.
Why the Standard Recommendation Is Too Low
The official Recommended Dietary Allowance for protein is 0.8 grams per kilogram of body weight, or about 0.36 grams per pound. For a 180-pound person, that’s only 65 grams a day. This number was set to prevent deficiency in sedentary adults, not to support muscle growth. It’s the bare minimum your body needs to maintain basic functions, and it falls well short of what active people require.
People who exercise regularly need at least 1.1 to 1.5 g/kg, and those who lift weights or train for endurance events need 1.2 to 1.7 g/kg. A large meta-analysis published in Frontiers in Nutrition found that 1.6 g/kg per day, combined with resistance training, was sufficient to maximize gains in lean mass, muscle strength, and overall performance in healthy young adults. Intakes above 1.5 g/kg showed no additional benefits for strength or endurance.
Your Target Range by Body Weight
Here’s what the 1.2 to 1.6 g/kg range looks like in practical terms:
- 140 lbs (64 kg): 77 to 102 g protein per day
- 160 lbs (73 kg): 88 to 117 g protein per day
- 180 lbs (82 kg): 98 to 131 g protein per day
- 200 lbs (91 kg): 109 to 146 g protein per day
- 220 lbs (100 kg): 120 to 160 g protein per day
If you carry a significant amount of body fat, basing calculations on your goal weight or lean body mass gives a more accurate target. Someone at 250 pounds with 35% body fat doesn’t need 200 grams of protein. Using a goal weight of 200 pounds would put them in a more reasonable range.
How to Spread Protein Across Meals
Your body can only ramp up muscle-building so fast in response to a single dose of protein. Research consistently shows that about 30 grams of protein in one meal is enough to maximally stimulate muscle protein synthesis. One study found that 90 grams of lean beef didn’t increase the muscle-building response any more than 30 grams did. Another found that eating more than 20 grams of whole-egg protein in one sitting didn’t push the response higher in young men.
That said, protein eaten beyond that 30-gram threshold isn’t wasted. Your body still absorbs and uses it for other functions, including energy and tissue repair. Research on intermittent fasting has shown that people who consume large amounts of protein in a short window maintain the same lean mass as those who spread it out more evenly. So meal timing matters, but it’s not a dealbreaker.
The strongest association with leg lean mass and strength came from eating 30 to 45 grams of protein per meal across multiple meals throughout the day. For most people, three to four protein-rich meals spaced a few hours apart is a practical and effective approach. If you’re aiming for 120 grams daily, that’s roughly 30 to 40 grams at each of three meals, with room for a snack.
Protein Before Bed
A pre-sleep protein dose can give your muscles extra raw material during the overnight fasting period. In one study, young men who consumed about 28 grams of protein before bed every night during a 12-week resistance training program gained more muscle mass and strength than those who didn’t. A slow-digesting protein source like cottage cheese, Greek yogurt, or a casein-based shake works well here because it releases amino acids gradually while you sleep.
When You Need More Than 1.6 g/kg
Two situations push your protein needs above the standard muscle-building range.
The first is cutting weight. When you’re eating fewer calories than you burn, your body is more likely to break down muscle for energy. Higher protein intake acts as a buffer against that muscle loss. Recommendations for athletes in a calorie deficit range from 1.6 to 2.4 g/kg per day, with resistance-trained athletes potentially benefiting from up to 2.7 g/kg. Above 2.4 g/kg, though, the additional muscle-sparing effect becomes negligible.
The second is age. Adults over 60 face what researchers call anabolic resistance: the muscle-building machinery becomes less responsive to both protein and exercise. Older adults need at least 1.0 to 1.2 g/kg just for maintenance, and those actively trying to build strength likely need to push toward the higher end of the muscle-building range. They also benefit from a higher amount of the amino acid leucine per meal, roughly 3 grams compared to the 2 grams that works for younger adults. Leucine is the specific amino acid that triggers the muscle-building process, and it’s found in high concentrations in dairy, eggs, meat, and fish.
Plant vs. Animal Protein Sources
Not all protein is equally effective at stimulating muscle growth. Animal-based sources like whey, eggs, dairy, meat, and fish tend to produce a stronger muscle-building response than plant sources like soy, wheat, or rice protein. This comes down to three factors: plant proteins generally contain fewer essential amino acids per gram, they’re often low in specific amino acids like lysine or leucine, and compounds naturally present in plant foods can reduce how much protein your body actually absorbs.
None of this means you can’t build muscle on a plant-based diet. It does mean you may need to eat slightly more total protein, combine different plant sources to cover amino acid gaps, and pay closer attention to getting enough leucine-rich foods. Soy, lentils, and quinoa are among the strongest plant options. Adding a small amount of a leucine-rich supplement or food to plant-based meals can help close the gap.
Practical Takeaways
For most people lifting weights and trying to build muscle, the target is straightforward: aim for 1.2 to 1.6 grams of protein per kilogram of body weight daily, spread across three to four meals of 30 to 45 grams each. If you’re over 60, push toward the higher end. If you’re in a calorie deficit, go higher still, up to about 2.4 g/kg. Prioritize protein sources with complete amino acid profiles, and consider a slow-digesting protein source before bed if your schedule allows it.
Beyond hitting these numbers, the most important variable is consistency, both with your protein intake and with your training. A perfect protein strategy with inconsistent workouts won’t produce results, and hard training with insufficient protein leaves gains on the table.