Most people need 1.4 to 2.0 grams of protein per kilogram of body weight per day to build muscle. For a 180-pound (82 kg) person, that works out to roughly 115 to 164 grams of protein daily. This range, established by the International Society of Sports Nutrition, covers the needs of most people who exercise regularly and want to gain muscle.
That said, your exact number depends on your age, whether you’re cutting calories, and how you spread your protein across the day. Here’s how to dial it in.
How to Calculate Your Target
Start by converting your body weight to kilograms (divide pounds by 2.2), then multiply by 1.6 as a practical middle-ground target. A 150-pound person (68 kg) lands at about 109 grams per day. A 200-pound person (91 kg) needs roughly 145 grams. If you’re newer to resistance training, the lower end of the 1.4 to 2.0 range is likely enough. If you’ve been lifting for years and are pushing hard, aim closer to 2.0 g/kg.
Going above 2.0 g/kg doesn’t appear to provide additional muscle-building benefits for most people, and Harvard Health notes you should be cautious about consistently exceeding 2 grams per kilogram. The exception is when you’re actively losing weight, which has its own requirements (more on that below).
Why Per-Meal Portions Matter
Your body can only use so much protein at once to stimulate muscle growth. The current recommendation is about 0.25 grams of high-quality protein per kilogram of body weight per meal, which translates to roughly 20 to 40 grams per sitting depending on your size. Eating 100 grams in one meal and skipping protein the rest of the day won’t produce the same results as spreading it out.
Ideally, you’d eat protein-rich meals every three to four hours across the day. For someone targeting 150 grams daily, that might look like four meals of 35 to 40 grams each. This keeps the muscle-building signal elevated throughout the day rather than spiking it once and letting it drop.
The amino acid leucine plays an outsized role in triggering muscle repair. You need at least 2 to 3 grams of leucine per meal to fully activate that process. Most servings of meat, fish, eggs, dairy, or a quality protein powder hit that threshold naturally at the 20 to 40 gram protein mark.
Protein Before Bed
A slower-digesting protein before sleep can extend the muscle-building window into the overnight hours. Research shows that 40 grams of casein protein (the kind found in milk and cottage cheese) before bed increases muscle protein synthesis during sleep, while 20 grams wasn’t enough to produce the same effect. If you’re serious about maximizing results, 30 to 40 grams of protein from cottage cheese, Greek yogurt, or a casein shake before bed is a simple addition to your routine.
Higher Needs When Cutting Calories
If you’re trying to lose fat while preserving muscle, your protein needs jump. When your body is in a calorie deficit, it’s more likely to break down muscle for energy unless you give it a strong reason not to. Guidelines for muscle preservation during weight loss recommend approximately 0.7 to 1.0 grams per pound of body weight, which can push intake to 2.3 to 3.1 g/kg for resistance-trained individuals. A 170-pound person dieting down might need 120 to 170 grams of protein per day, even higher than someone eating at maintenance calories.
This is one of the few situations where exceeding 2.0 g/kg makes sense. The extra protein helps protect lean mass while your body taps into fat stores for energy.
Adjustments for Adults Over 50
Muscle becomes harder to build and easier to lose as you age. Nearly half of all protein in the body is stored in muscle, and muscle mass naturally declines over time, a process called sarcopenia. Older adults develop what researchers call “anabolic resistance,” meaning the same amount of protein that triggers robust muscle growth in a 25-year-old produces a weaker response in a 60-year-old.
For this reason, adults over 50 benefit from aiming at the higher end of the range: 1.2 to 1.6 grams per kilogram daily, rather than the standard 0.8 g/kg general health recommendation. For a 180-pound older adult, that’s roughly 100 to 130 grams per day. Hitting the leucine threshold at each meal becomes especially important, since older muscles need a stronger amino acid signal to respond. Aim for at least 30 to 40 grams of protein per meal rather than 20.
Plant Protein vs. Animal Protein
Plant-based protein sources can build muscle just as effectively as animal sources, as long as the total protein and amino acid content is comparable. Studies comparing whey and plant-based protein powders show equivalent muscle growth when the servings contain similar amounts of protein and branched-chain amino acids. A good benchmark for any protein powder, plant or animal, is 20 to 30 grams of protein per serving with at least 1 to 3 grams of leucine.
The practical challenge with whole-food plant proteins (beans, lentils, tofu) is that they’re less protein-dense per calorie, so you need to eat more volume. They also tend to be lower in leucine individually, which means combining sources or slightly increasing total intake helps close the gap. If you’re fully plant-based, aiming for the higher end of the 1.4 to 2.0 g/kg range is a reasonable strategy.
Is High Protein Safe?
For healthy people, high-protein diets are not known to cause medical problems. The longstanding concern about protein damaging kidneys doesn’t hold up in people with normal kidney function. However, high protein intake can worsen kidney function in people who already have kidney disease, because the body may struggle to clear all the waste products from protein metabolism. If you have existing kidney disease or diabetes, talk with your doctor before significantly increasing protein.
For everyone else, the practical ceiling is around 2.0 g/kg for muscle building at maintenance calories, and up to 3.1 g/kg during aggressive fat loss phases. Beyond those ranges, you’re unlikely to see additional muscle benefits and you’re simply adding calories your body doesn’t need for that purpose.