Most people looking to build muscle need between 1.6 and 2.2 grams of protein per kilogram of body weight each day. For a 180-pound (82 kg) person, that works out to roughly 130 to 180 grams of protein daily. This range, combined with consistent resistance training, is enough to maximize gains in lean mass and strength for most healthy adults.
That target is significantly higher than the general dietary recommendation of 0.8 grams per kilogram, which is designed to prevent deficiency, not to optimize muscle growth. If you’ve been eating at that baseline level, you likely have a lot of room to increase your intake and see results.
How to Calculate Your Personal Target
The simplest method is to multiply your body weight in kilograms by 1.6 on the low end and 2.2 on the high end. If you think in pounds, divide your weight by 2.2 first to get kilograms, or just aim for roughly 0.7 to 1.0 gram per pound of body weight. Here’s what that looks like at common body weights:
- 150 lbs (68 kg): 109–150 g protein per day
- 180 lbs (82 kg): 131–180 g protein per day
- 200 lbs (91 kg): 146–200 g protein per day
- 220 lbs (100 kg): 160–220 g protein per day
If you carry a significant amount of body fat, using your goal weight or estimated lean mass gives a more accurate number. Someone who weighs 250 pounds but carries 80 pounds of fat doesn’t need to eat protein as if all 250 pounds are muscle tissue. Using a target weight of 200 pounds in that scenario is more practical.
Where you land in the 1.6 to 2.2 range depends on a few factors. If you’re in a calorie deficit (trying to lose fat while building or preserving muscle), aiming toward the higher end helps protect lean mass. If you’re eating at maintenance or in a surplus, the lower end of the range is typically sufficient.
Why 1.6 Grams Per Kilogram Is the Key Threshold
A large body of research points to 1.6 grams per kilogram per day as the point where muscle-building benefits plateau for most young, healthy adults doing resistance training. Below that number, you’re likely leaving gains on the table. Above it, you still get some benefit, but the returns diminish. A well-known meta-analysis by Morton and colleagues found that this intake level was sufficient to maximize gains in lean mass, muscle strength, and overall performance, and that it was safely tolerated.
That said, “diminishing returns” doesn’t mean “zero returns.” Recent research published in Cell Reports Medicine challenged the old assumption that your body can only use a fixed amount of protein at once. When researchers gave participants 100 grams of protein after exercise and tracked amino acid use over 12 hours, they found a dose-dependent increase in muscle protein building, with minimal waste through oxidation. The body’s capacity to incorporate protein into muscle tissue appears to be larger and longer-lasting than previously thought. So eating above 1.6 g/kg won’t be wasted, it just won’t double your results.
How to Spread Protein Across Your Day
You’ve probably heard that your body can only absorb 20 to 25 grams of protein per meal. That’s an oversimplification. The 20-to-25-gram figure comes from studies using fast-absorbing protein supplements like whey, consumed in isolation. When you eat whole-food protein sources like chicken, eggs, beans, or dairy, digestion slows down and your body has more time to use the amino acids. The absorption ceiling doesn’t apply the same way.
Still, spreading your protein across at least three to four meals is a smart strategy. Each time you eat a sufficient dose of protein, you trigger a burst of muscle protein synthesis. Cramming your entire daily target into one meal would give you fewer of those anabolic spikes throughout the day, limiting your total muscle-building response. Aim for 25 to 40 grams per meal depending on your size and age, and you’ll cover your bases without overthinking it.
Post-workout protein matters, but it’s not as urgent as supplement marketing suggests. The recommendation for immediately after exercise is about 0.25 to 0.30 grams per kilogram of body weight, which works out to roughly 20 to 25 grams for most people. A regular meal within a couple of hours after training accomplishes the same thing.
Protein Needs After Age 50
Older adults need more protein per meal to get the same muscle-building effect as younger people. This is due to a phenomenon called anabolic resistance: as you age, your muscles become less responsive to the protein you eat. A 25-year-old might stimulate strong muscle protein synthesis with just 20 grams of protein in a meal. Research from Stanford Lifestyle Medicine found that adults around age 71 were completely unresponsive to that same 20-gram dose and needed 40 grams to trigger a comparable response.
The practical recommendation for adults over 50 is to aim for 0.4 grams per kilogram of body weight at each meal, which translates to about 30 to 35 grams per sitting for an average-sized person. Across a full day, this puts total intake well above the general 0.8 g/kg guideline. If you’re over 50 and actively training, targeting the higher end of the 1.6 to 2.2 range makes sense.
Plant Protein Versus Animal Protein
Plant proteins work for muscle building, but they require more planning. Most plant sources are lower in one or more essential amino acids, particularly leucine, which is the specific amino acid that acts as the “trigger” for muscle protein synthesis. You need roughly 2 to 3 grams of leucine per meal to fully activate that process, and plant proteins deliver less leucine per gram than animal sources like whey, eggs, or meat.
To compensate, younger adults eating a fully plant-based diet should aim for at least 20% more total protein per meal than omnivores. Older plant-based eaters may need 30% more. In practical terms, that means targeting at least 30 grams of plant protein per meal if you’re under 50, and at least 40 grams if you’re older. Combining different plant proteins (rice and beans, for example) helps balance out amino acid profiles, though it can add calories. Athletes managing body fat on a calorie-restricted plant-based diet may find this challenging, since plant protein sources tend to be more calorie-dense relative to their protein content.
Mixing even small amounts of animal protein with plant sources dramatically closes the gap. Blending strategies require only about 1.05 to 1.4 times the total protein to cover all essential amino acid needs, compared to the larger increases needed on a fully vegan diet.
Is High Protein Intake Safe?
For people with healthy kidneys, high-protein diets in the ranges discussed here are not known to cause medical problems. The concern about protein damaging kidneys comes from research on people who already have kidney disease, where the kidneys struggle to filter the byproducts of protein metabolism. In healthy individuals, the kidneys handle elevated protein intake without issue.
The most common side effect of dramatically increasing protein is digestive discomfort, which usually resolves as your body adjusts. Staying hydrated helps, since protein metabolism requires more water than fat or carbohydrate metabolism. If you have existing kidney concerns, those conversations belong with your doctor, but the 1.6 to 2.2 g/kg range has been studied extensively and is considered safe and well-tolerated in healthy populations.