To gain muscle, most people need between 1.4 and 2.0 grams of protein per kilogram of body weight per day. For a 180-pound (82 kg) person, that works out to roughly 115 to 164 grams daily. The exact number depends on your age, body composition, training intensity, and whether you’re cutting or bulking. Below is everything you need to calculate your personal target.
The Basic Calculation
The International Society of Sports Nutrition recommends 1.4 to 2.0 g/kg/day for building and maintaining muscle in exercising individuals. Here’s how to use that range:
- Step 1: Convert your body weight to kilograms (divide pounds by 2.2).
- Step 2: Multiply by 1.6 g/kg as a solid starting point for most lifters.
- Step 3: Adjust up or down based on the factors in the sections below.
A 150-pound person (68 kg) would aim for about 109 grams per day at the 1.6 g/kg midpoint. A 200-pound person (91 kg) would target around 145 grams. If you’re training hard four or more days per week and prioritizing muscle growth, moving toward 2.0 g/kg is reasonable.
Why Body Composition Matters More Than Scale Weight
Standard protein calculators use total body weight, but that approach has a notable flaw. Two people who weigh 220 pounds can have vastly different body fat levels. One might carry 180 pounds of lean mass, the other 150. Since protein primarily supports muscle tissue, the person with more lean mass genuinely needs more protein, and the person carrying more fat may overshoot their target by using total weight alone.
Research increasingly suggests that lean body mass provides a more accurate basis for protein calculations. If you know your body fat percentage (from a DEXA scan, a reliable scale, or even a rough estimate), subtract your fat mass from your total weight. Then apply a slightly higher multiplier of about 2.2 to 2.6 g per kilogram of lean mass, which typically lands you in the same neighborhood as 1.6 to 2.0 g/kg of total weight but with better precision. If you don’t know your body fat percentage, using total body weight at 1.6 to 2.0 g/kg works well enough for most people.
How to Spread Protein Across Your Day
Your body doesn’t use protein in one massive dump. Muscle protein synthesis peaks at a specific dose per meal, then additional protein gets used for energy or other body functions rather than extra muscle building. For younger adults, that ceiling sits around 0.25 to 0.40 g/kg per meal, which translates to roughly 20 to 40 grams depending on your size.
The practical strategy: eat at least four protein-rich meals spaced three to four hours apart. If your daily target is 160 grams, that’s about 40 grams per meal across four meals. This distribution matters. Eating 80 grams at dinner and 10 grams at breakfast is less effective than splitting it evenly, even if the daily total is the same.
Each of those meals should contain enough of the amino acid leucine to trigger the muscle-building process. The threshold is roughly 2 to 3 grams of leucine per serving, which you’ll naturally hit with 25 to 30 grams of high-quality protein from sources like chicken, eggs, Greek yogurt, or whey.
Adjustments for Age
If you’re over 50, your muscles become less responsive to protein. This is called anabolic resistance. It’s not that your body can’t build muscle anymore; it just needs a louder signal to get started. In one study, men around age 22 responded to 20 grams of protein per meal, while men around age 71 needed 40 grams to get the same muscle-building response. That’s double the dose for the same effect.
Stanford Lifestyle Medicine recommends adults over 50 consume 1.2 to 1.6 g/kg per day, with at least 30 to 35 grams per meal. If you’re 165 pounds and over 50, that means roughly 30 grams minimum at each sitting, not the 20 grams that might suffice for someone in their twenties.
Adjustments for Cutting and Weight Loss
When you’re eating in a caloric deficit, your protein needs go up, not down. Your body is more likely to break down muscle for energy when calories are restricted, and higher protein intake counteracts this. Research shows that intake exceeding 1.3 g/kg per day can actually increase muscle mass during weight loss, while dropping below 1.0 g/kg significantly raises the risk of losing muscle.
For resistance-trained individuals trying to get lean, the evidence supports going as high as 2.3 to 3.1 g/kg per day during aggressive cuts. That’s substantially higher than the standard muscle-building range. If you’re dieting hard and lifting, this is the single most important nutritional lever for keeping the muscle you’ve built.
Plant-Based Protein: Do You Need More?
The short answer is: not necessarily, as long as you’re hitting your total daily target and getting enough essential amino acids. Multiple studies comparing plant-based proteins like rice, pea, and soy to whey found no differences in muscle growth or strength when daily protein intake was matched. Once you’re consuming at least 1.6 g/kg per day, the source appears to play a minor role.
That said, many plant proteins are lower in leucine per gram, so you may need slightly larger servings to hit that 2 to 3 gram leucine trigger per meal. Combining different plant sources (rice and pea protein together, for example) helps fill in amino acid gaps. If you eat a varied plant-based diet and hit your total daily number, you’re not at a disadvantage for building muscle.
Quick Reference by Body Weight
These ranges use the 1.6 to 2.0 g/kg range for active individuals focused on muscle gain:
- 130 lbs (59 kg): 94 to 118 g/day
- 150 lbs (68 kg): 109 to 136 g/day
- 170 lbs (77 kg): 123 to 154 g/day
- 190 lbs (86 kg): 138 to 172 g/day
- 210 lbs (95 kg): 152 to 190 g/day
- 230 lbs (105 kg): 168 to 210 g/day
Use the lower end if you’re newer to training or at a higher body fat percentage. Use the upper end if you’re lean, training intensely, or in a caloric deficit.
Is There a Safe Upper Limit?
For people with healthy kidneys, high protein intake does not appear to cause kidney damage. An 11-year observational study found that increased protein had no measurable effect on kidney function in women with normal renal health. The concern is real, however, for people who already have reduced kidney function or only one kidney, where intake above 1.2 g/kg per day warrants caution.
Some research has explored intakes above 3.0 g/kg per day in resistance-trained individuals and found positive effects on body composition with no adverse health outcomes. That doesn’t mean everyone needs that much. For most lifters, 1.6 to 2.2 g/kg per day covers the muscle-building bases without requiring you to eat chicken at every meal.