Most people need 1.4 to 2.0 grams of protein per kilogram of body weight per day to build muscle, assuming they’re also doing resistance training. For a 180-pound (82 kg) person, that works out to roughly 115 to 164 grams of protein daily. The exact number depends on your age, whether you’re cutting or bulking, and how you spread that protein across meals.
Your Daily Protein Target
The International Society of Sports Nutrition sets the general range at 1.4 to 2.0 g/kg/day for building and maintaining muscle mass. If you prefer pounds, that translates to about 0.6 to 0.9 grams per pound of body weight. Most people do well landing somewhere in the middle of that range, around 0.7 to 0.8 grams per pound.
Here’s what that looks like for different body weights:
- 140 lbs (64 kg): 90–128 g protein per day
- 160 lbs (73 kg): 102–146 g per day
- 180 lbs (82 kg): 115–164 g per day
- 200 lbs (91 kg): 127–182 g per day
- 220 lbs (100 kg): 140–200 g per day
If you’re significantly overweight, base your calculation on your goal body weight or lean body mass rather than your total weight. Otherwise, the number inflates beyond what your muscles actually need.
How Much Per Meal Actually Matters
Your body can only use so much protein at once for muscle building. The sweet spot per meal is about 0.3 g/kg of body weight, which falls in the range of 20 to 40 grams for most people. Eating more than 40 grams in a single sitting doesn’t appear to stimulate additional muscle growth compared to the 20–40 gram range.
This means spreading your intake across the day matters. Eating 150 grams of protein in two massive meals is less effective than distributing it across four or five meals and snacks spaced roughly three to four hours apart. Each feeding is a separate opportunity to trigger muscle protein synthesis, and you want to take advantage of as many of those windows as possible throughout the day.
A protein-rich snack before bed can also help. Consuming 30 to 40 grams of slow-digesting protein (like cottage cheese or a casein-based shake) before sleep increases overnight muscle protein synthesis and boosts metabolic rate.
What Happens When You’re Cutting
If you’re eating in a caloric deficit to lose fat, your protein needs go up, not down. The recommended range during weight loss shifts to 1.6 to 2.4 g/kg/day. A more aggressive deficit demands the higher end of that range because faster fat loss tends to pull muscle mass along with it.
The research on this is striking. In one study, resistance-trained athletes eating only 1 g/kg/day during a 40% calorie deficit lost 1.6 kg of lean body mass in just two weeks. Athletes eating 2.3 g/kg/day in the same deficit lost only 0.3 kg. In a separate trial, overweight but trained young men eating 2.4 g/kg/day during a 40% deficit actually gained lean mass over four weeks while also losing fat, provided they combined it with resistance training and high-intensity interval work. Even the lower-protein group in that study, at 1.2 g/kg/day, managed to maintain their muscle.
The takeaway: if you’re trying to get leaner while keeping your muscle, protein becomes your most important macronutrient. Intakes above 2.4 g/kg/day don’t appear to offer additional muscle-sparing benefits.
Protein Needs After 50
Older adults need more protein per meal and per day to get the same muscle-building response as younger people. This is because of a phenomenon called anabolic resistance, where aging muscles become less responsive to the protein you eat. The gut absorbs fewer amino acids after a meal, blood flow to muscles drops after eating, and the molecular signals that trigger muscle repair become blunted.
The European Society for Clinical Nutrition and Metabolism recommends at least 1.0 to 1.2 g/kg/day for healthy adults over 65, with 1.2 to 1.5 g/kg/day for those dealing with chronic illness. That’s notably higher than the standard recommended dietary allowance of 0.8 g/kg/day, which research increasingly suggests is insufficient for older adults trying to maintain or build muscle. To compensate for anabolic resistance, older adults also benefit from aiming for the higher end of per-meal protein intake, closer to 40 grams, to reach the threshold that kicks muscle protein synthesis into gear.
Plant Protein vs. Animal Protein
A meta-analysis of randomized controlled trials found that protein source did not affect changes in total lean mass or muscle strength. Whether your protein comes from chicken, whey, soy, or pea protein, the absolute muscle you build is comparable, as long as total intake and training are matched.
There is one nuance. Animal protein showed a slight advantage in percent lean mass, particularly in adults under 50. The likely explanation is amino acid composition. Animal proteins tend to be richer in leucine, the amino acid that acts as the primary trigger for muscle protein synthesis. You need roughly 2 to 3 grams of leucine per meal to fully activate that process. Most animal protein sources hit that threshold easily in a 25–30 gram serving. Plant sources can get there too, but you may need a slightly larger portion or a blend of sources (combining legumes with grains, for instance) to match the leucine content.
The Post-Workout Window Is Wider Than You Think
The idea that you need to chug a protein shake within 30 minutes of your last set is largely a myth. The so-called “anabolic window” likely extends five to six hours around your training session, not 30 to 60 minutes.
In a controlled trial, resistance-trained men were split into two groups: one consumed protein before exercise, the other after. After 10 weeks, both groups showed similar gains in muscle size and strength. The narrow window theory didn’t hold up.
The one exception is fasted training. If you work out first thing in the morning without eating, the window does tighten, and getting protein in sooner after training becomes more important. But if you ate a meal containing protein within a few hours before lifting, there’s no rush. Your pre-workout meal is already supplying amino acids to your muscles during and after the session. The recommended protein intake around training is 0.4 to 0.5 g/kg of lean body mass, or roughly 20 to 40 grams for most people.
Putting It All Together
For most people lifting weights and trying to add muscle, the practical plan looks like this: aim for 1.6 to 2.0 g/kg/day as your daily target, split across four or more meals of 20 to 40 grams each, spaced three to four hours apart. If you’re in a caloric deficit, push toward 2.0 to 2.4 g/kg/day. If you’re over 60, start at 1.2 g/kg/day minimum and lean toward higher per-meal doses. Prioritize total daily intake over post-workout timing, and if you eat plant-based, pay attention to portion sizes to ensure you’re hitting enough leucine at each meal.
Safety isn’t a real concern at these levels. Studies lasting up to two years have shown no health problems in healthy people consuming up to 4.4 g/kg/day, well above what anyone needs for muscle growth. The practical ceiling is appetite and convenience, not risk.