Most people who lift weights need between 1.4 and 2.0 grams of protein per kilogram of body weight each day to build muscle. For a 180-pound (82 kg) person, that works out to roughly 115 to 164 grams of protein daily. That range, established by the International Society of Sports Nutrition, covers the vast majority of people training for size and strength. Where you fall within it depends on your training intensity, your age, and whether you’re also trying to lose fat.
The Daily Target in Grams
The simplest way to find your number is to convert your body weight to kilograms (divide pounds by 2.2) and multiply by 1.4 on the low end or 2.0 on the high end. Someone weighing 150 pounds (68 kg) would aim for 95 to 136 grams per day. Someone at 200 pounds (91 kg) would target 127 to 182 grams.
Mayo Clinic places the range slightly lower, at 1.2 to 1.7 grams per kilogram, for people who regularly lift weights or train for endurance events. The difference reflects that the ISSN recommendation is geared specifically toward maximizing muscle gain, while Mayo’s figure covers general performance needs. If your primary goal is adding muscle, the 1.4 to 2.0 range is the better target.
Going above 2.0 grams per kilogram is unlikely to build more muscle in most people, but there is some evidence that very high intakes (above 3.0 g/kg/day) can help resistance-trained individuals lose fat. That level isn’t necessary for beginners or intermediate lifters, and eating that much protein takes deliberate effort.
Why Cutting Calories Changes the Math
If you’re trying to lose fat and build muscle at the same time, you need more protein than someone eating at maintenance. A well-known trial put young men on a 40% calorie deficit with intense exercise and compared two protein levels: 1.2 grams per kilogram per day versus 2.4 grams per kilogram per day. The higher-protein group gained 1.2 kg of lean mass over four weeks while losing 4.8 kg of fat. The lower-protein group gained almost no lean mass and lost less fat (3.5 kg).
That’s a striking difference. When calories are restricted, your body is more likely to break down muscle for energy. Eating closer to 2.4 grams per kilogram counteracts that signal and gives your muscles enough raw material to recover and grow even in a deficit. If you’re dieting, aim for the upper end of the range or slightly above it.
How to Spread Protein Across Meals
Total daily protein matters most, but how you distribute it throughout the day makes a measurable difference. Research on lean mass and leg strength found that eating at least two meals per day containing 30 to 45 grams of protein each produced the strongest results. People who hit that per-meal threshold in two daily meals had significantly more leg lean mass and strength than people who never reached it in a single meal.
The benefit plateaued at around 45 grams per meal when people ate two high-protein meals, and at 30 grams per meal when they ate only one. In practical terms, this means spreading your protein across three or four meals of roughly 30 to 40 grams each is more effective than eating a small amount at breakfast and lunch, then cramming 80 grams into dinner. Each meal should contain enough protein to cross that 30-gram floor.
What Triggers Muscle Repair
Your muscles respond to protein in a dose-dependent way up to a point. The key driver is an amino acid called leucine, which acts as a biochemical trigger for muscle repair. Research suggests that roughly 2.5 to 3 grams of leucine per meal is needed to fully activate that repair process. A typical 30-gram serving of animal protein contains about 2.5 to 3 grams of leucine naturally, which is one reason the 30-gram-per-meal threshold lines up so well with the research on lean mass.
Plant proteins tend to contain less leucine per gram, so if you’re getting most of your protein from beans, lentils, tofu, or grains, you may need a somewhat larger serving to hit the same leucine threshold. Combining different plant sources at each meal (rice and beans, for example) also helps fill gaps in individual amino acid profiles.
Protein Needs After 50
As you age, your muscles become less responsive to the protein you eat. This phenomenon, sometimes called anabolic resistance, means older adults need more protein per meal and per day to get the same muscle-building effect a younger person would. Nearly half of all the protein in your body is stored in muscle, and muscle mass naturally declines with age. That decline increases fall risk, reduces independence, and raises the likelihood of hospitalization.
The current official recommendation for older adults is the same as for younger adults (0.8 g/kg/day), but researchers now widely consider that too low. The Administration for Community Living and multiple research groups recommend that older adults consume at least 1.0 to 1.2 grams per kilogram daily just to maintain muscle, even without intense exercise. Older adults who are actively strength training should aim for the same 1.4 to 2.0 g/kg range as younger lifters, and they benefit even more from reaching that 30-gram-per-meal threshold at every meal.
Putting the Numbers Together
Here’s a quick reference based on a few common body weights, using the 1.4 to 2.0 g/kg range:
- 130 lbs (59 kg): 83 to 118 g protein per day
- 155 lbs (70 kg): 98 to 140 g protein per day
- 180 lbs (82 kg): 115 to 164 g protein per day
- 205 lbs (93 kg): 130 to 186 g protein per day
If you’re cutting calories, push toward or slightly beyond the top of the range. If you’re eating at maintenance or in a surplus and training consistently, the middle of the range is sufficient for most people. Spread that total across at least three meals, each containing a minimum of 30 grams. Prioritize protein sources that are rich in leucine (meat, fish, dairy, eggs, soy) or combine plant sources to compensate.
Consistency matters more than precision. Hitting 1.6 grams per kilogram every day for months will produce far better results than alternating between 0.8 one day and 2.4 the next. Track loosely for a week or two to get a feel for what your meals look like at the right protein level, then let the habit carry you.