Most adults need at least 0.8 grams of protein per kilogram of body weight per day, which works out to roughly 55 grams for a 150-pound person. But that number is a floor, not a target. Depending on your age, activity level, and goals, your ideal intake could be significantly higher.
The Baseline for Sedentary Adults
The Recommended Dietary Allowance (RDA) of 0.8 grams per kilogram of body weight was set using nitrogen balance studies, which measure whether your body is breaking down more protein than it’s building. At 0.8 g/kg, most people maintain equilibrium. For a 180-pound person, that’s about 65 grams per day. For someone at 130 pounds, it’s roughly 47 grams.
This amount prevents deficiency, but it wasn’t designed to optimize muscle, recovery, or long-term health. Think of it as the minimum to keep things running, not the amount that helps you thrive. Federal dietary guidelines also frame protein as a percentage of total calories: adults 19 and older should get 10 to 35 percent of their daily calories from protein. On a 2,000-calorie diet, that range translates to 50 to 175 grams per day, which is a wide window.
How Much You Need for Muscle and Strength
If you exercise regularly or want to build or maintain muscle, the RDA falls short. Sports nutrition researchers largely agree that 1.6 to 2.2 grams per kilogram of body weight per day maximizes muscle protein synthesis, the process your body uses to repair and grow muscle tissue. For a 150-pound person, that’s 109 to 150 grams daily. For someone at 200 pounds, it’s 145 to 200 grams.
Going above 2.2 g/kg doesn’t appear to offer additional muscle-building benefits for most people. The key factor at higher intakes is consistency. Hitting your target regularly matters more than the exact number you land on within that range, so pick a level you can realistically sustain through whole foods, shakes, or whatever combination works for your routine.
Spreading Protein Across Meals
Your body can digest and absorb large amounts of protein in a single sitting, but muscle protein synthesis has a ceiling per meal. Research shows that roughly 30 grams of protein in one meal is enough to maximally stimulate muscle repair, and going higher than that in a single sitting doesn’t boost the response much further. Some evidence pushes that ceiling closer to 45 grams per meal for people eating at least two high-protein meals a day.
The practical takeaway: rather than loading 80 grams into one meal and eating very little protein the rest of the day, spreading your intake across three or four meals produces a stronger association with lean mass and strength. If your daily target is 120 grams, aiming for 30 to 40 grams at each of three meals gets you there while keeping each dose in the range your muscles can use most efficiently.
Higher Needs After 65
Aging brings a gradual loss of muscle mass called sarcopenia. Starting around your 30s, you lose a small percentage of muscle each decade, and the rate accelerates after 65. One reason is that older muscles become less responsive to protein, meaning you need more of it to trigger the same repair process a younger person gets from a smaller dose.
Researchers recommend that adults over 65 aim for 1.0 to 1.2 grams per kilogram of body weight daily, which is 25 to 50 percent more than the standard RDA. For a 160-pound older adult, that’s 73 to 87 grams per day. Pairing adequate protein with resistance or endurance exercise amplifies the benefit, helping preserve both muscle mass and functional strength.
When You May Need Less
People with chronic kidney disease are often advised to eat less protein than the general population, because the kidneys are responsible for filtering the byproducts of protein metabolism. When kidney function is reduced, a lower protein diet can help slow the progression of the disease. The exact restriction depends on the stage of kidney disease, body size, and nutritional status, so there’s no single number that applies to everyone in this group. If you have kidney concerns, a dietitian who specializes in renal nutrition can set a target that protects kidney function without risking malnutrition.
Putting It All Together
Here’s a quick reference based on body weight:
- Sedentary adults: 0.8 g/kg (about 55 g/day for a 150-lb person)
- Active adults building muscle: 1.6 to 2.2 g/kg (109 to 150 g/day at 150 lbs)
- Adults over 65: 1.0 to 1.2 g/kg (68 to 82 g/day at 150 lbs)
- Overall calorie share: 10 to 35 percent of total daily calories
To find your number in grams, divide your weight in pounds by 2.2 to get kilograms, then multiply by the g/kg target that fits your situation. Most healthy adults eating a varied diet that includes meat, dairy, legumes, or eggs reach the RDA without trying. Getting into the 1.6+ g/kg range takes more intentional planning: adding a protein source to every meal, keeping high-protein snacks on hand, or supplementing with a shake when whole food isn’t convenient.