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 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 mass.
Where you fall within that range depends on several factors: your age, whether you’re trying to lose fat at the same time, how you spread protein across your meals, and where your protein comes from.
The Daily Target in Practical Terms
The simplest way to calculate your protein goal is to multiply your body weight in kilograms by 1.6 to 2.0. If you think in pounds, divide your weight by 2.2 first to get kilograms, then multiply. Here’s what that looks like at different body weights:
- 140 lbs (64 kg): 102 to 128 g per day
- 160 lbs (73 kg): 117 to 146 g per day
- 180 lbs (82 kg): 131 to 164 g per day
- 200 lbs (91 kg): 146 to 182 g per day
- 220 lbs (100 kg): 160 to 200 g per day
Multiple researchers have independently converged on similar numbers. Across seven major studies summarized in the sports nutrition literature, recommendations ranged from 1.2 g/kg on the low end to 2.0 g/kg on the high end, with most clustering around 1.6 to 1.8 g/kg. If you want one number to aim for, 1.6 g/kg is a reliable starting point for most lifters.
Why You Need More When Cutting Weight
If you’re eating in a caloric deficit to lose fat while trying to hold onto muscle, your protein needs go up significantly. The standard muscle-building range of 1.4 to 2.0 g/kg assumes you’re eating enough total calories. When calories drop, your body becomes more likely to break down muscle for energy, and extra protein helps counteract that.
For resistance-trained individuals in a caloric deficit, protein intakes of 2.3 to 3.1 g/kg per day may be necessary to maximize lean mass retention. That’s a substantial jump. For a 180-pound person, this means potentially eating 189 to 254 grams of protein daily during a cut. The leaner you are and the more aggressively you’re dieting, the closer you should aim to the upper end of that range.
How to Spread Protein Across Meals
Your body doesn’t use protein in one massive dump. Eating 130 grams at dinner and skipping it the rest of the day won’t produce the same results as distributing it evenly. Research on meal-level protein doses suggests aiming for about 0.4 g/kg per meal across at least four meals to reach the minimum effective daily total of 1.6 g/kg.
For someone weighing 82 kg (180 lbs), that’s roughly 33 grams per meal across four meals. If you’re targeting the higher end of the daily range (2.2 g/kg), you’d need about 0.55 g/kg per meal, or around 45 grams per sitting. The reason this matters comes down to a trigger mechanism in your muscles. Each time you eat protein, you need enough of the amino acid leucine (roughly 3 to 4 grams per meal) to flip the switch on muscle protein synthesis. A meal with 25 to 30 grams of high-quality protein typically delivers that threshold. Meals with only about 15 grams of protein fall short, providing less than 2 grams of leucine.
A Pre-Sleep Meal Can Help
One of the easiest ways to add a fourth protein feeding is a pre-sleep snack. Research on slow-digesting protein consumed before bed shows that 40 grams of casein (the primary protein in cottage cheese and casein supplements) boosted overnight muscle protein synthesis by about 22% compared to a placebo in recreational athletes who trained in the evening.
Interestingly, the dose matters here more than you might expect. Studies comparing 20 grams versus 40 grams of casein before bed found that 20 grams did not produce a significant increase in overnight muscle building compared to a placebo, while 40 grams consistently did, in both younger and older adults. If you’re going to eat before bed for muscle recovery, aim for the higher end. A cup of cottage cheese or a casein shake gets you close.
Plant Protein vs. Animal Protein
Plant-based proteins can absolutely support muscle growth, but you may need to eat more of them. Plant sources like beans, lentils, tofu, and grains tend to be lower in leucine and sometimes lack one or more essential amino acids in sufficient quantities. Research comparing soy and whey protein found no significant differences in muscle growth or strength when the two were matched for leucine content. The key phrase there is “matched for leucine.” When plant protein is consumed without accounting for its lower leucine concentration, you generally need a higher total dose to get the same muscle-building signal.
If you eat a fully plant-based diet, aiming for the upper end of the protein range (closer to 2.0 g/kg) and combining different plant sources throughout the day helps ensure you’re getting enough of every essential amino acid. Adding a small amount of supplemental leucine to plant-based meals is another strategy, though simply eating more total protein accomplishes the same thing.
Protein Needs After Age 50
Older adults face a challenge called anabolic resistance: their muscles require a stronger protein signal to initiate the same building response that comes easily in younger people. Per-meal protein ceilings reflect this. Younger men can maximize muscle protein synthesis with roughly 0.4 g/kg per meal, while older men may need up to 0.6 g/kg per meal to achieve the same effect.
Daily totals need to increase accordingly. Research on older men found that increasing protein intake by more than 0.54 g/kg per day above their habitual intake was associated with meaningful gains in muscle mass. For older women, the bar appears even higher. An increase of 0.57 g/kg per day above habitual intake was not enough to improve muscle mass in older women, suggesting they face greater anabolic resistance than men of the same age. This means older adults, particularly women, should prioritize protein at every meal and aim for the higher end of the 1.6 to 2.0 g/kg range or beyond.
Is High Protein Safe for Your Kidneys?
The concern that high-protein diets damage kidneys is one of the most persistent nutrition worries, and the evidence doesn’t support it for healthy people. A systematic review and meta-analysis of 28 trials covering 1,358 participants compared high-protein diets (1.5 g/kg or more) to normal-protein diets. While kidney filtration rates were slightly higher during high-protein eating, the actual change in kidney function over time did not differ between groups. In other words, the kidneys work a little harder to process more protein, but this doesn’t translate into damage or decline.
This applies to people with healthy kidneys. If you have existing kidney disease or are at high risk for it, the calculus changes, and protein intake should be managed more carefully.
Putting It All Together
Your daily protein target depends on your situation. For most people lifting weights and eating enough calories, 1.6 to 2.0 g/kg per day is the range backed by the strongest evidence. If you’re dieting, push that to 2.3 to 3.1 g/kg. If you’re over 50, aim for the higher end and pay extra attention to getting enough per meal, not just per day. Spread your intake across at least four meals with 25 to 40 grams each, and consider a 40-gram casein-rich snack before bed if you train in the evening. If you eat plant-based, increase your total intake or ensure you’re matching the leucine content of animal-based diets. The numbers aren’t complicated, but hitting them consistently, day after day, is what actually builds muscle.