Most adults should get 10% to 35% of their daily calories from protein, according to the National Academy of Medicine. That’s a wide range, and where you fall within it depends on your age, activity level, and goals. For a person eating 2,000 calories a day, 10% means about 50 grams of protein, while 35% means roughly 175 grams.
Recent updates to federal dietary guidelines have shifted the conversation, though. The old recommendation of 0.8 grams per kilogram of body weight held for decades, but revised guidelines now suggest 1.2 to 1.6 grams per kilogram. For a 150-pound person, that works out to about 80 to 110 grams a day, which typically lands in the 15% to 25% range depending on total calorie intake.
How to Calculate Your Protein Percentage
Protein has 4 calories per gram, so the math is straightforward. If you eat 100 grams of protein in a day, that’s 400 calories from protein. Divide that by your total daily calories and multiply by 100. On a 2,000-calorie diet, 400 protein calories equals 20%.
The percentage framing is useful for planning meals, but grams per kilogram of body weight gives you a more personalized target. To find yours, divide your weight in pounds by 2.2 to get kilograms, then multiply by your target range. Most healthy adults do well between 1.2 and 1.6 grams per kilogram.
The Best Range for Weight Loss
If you’re trying to lose weight, aiming for 20% to 30% of your calories from protein is a practical target. Protein is the most filling macronutrient. It slows digestion and influences hormones that signal fullness, so meals with adequate protein tend to keep you satisfied longer and reduce the urge to snack between meals.
Higher protein intake also helps preserve muscle while you’re in a calorie deficit. When you eat less than your body burns, you lose a mix of fat and muscle. Getting enough protein tips that ratio toward fat loss and away from muscle loss, which matters both for how you look and for keeping your metabolism from slowing down as you diet.
Protein Needs for Exercise and Muscle Building
People who lift weights or train seriously need more protein than sedentary adults. The current evidence points to 1.6 to 2.2 grams per kilogram of body weight per day for maximizing muscle growth and strength gains. For a 180-pound person, that’s roughly 130 to 180 grams daily, which could represent 25% to 35% of total calories depending on how much you eat overall.
Spreading protein across multiple meals matters too. Your body can only use so much at once for muscle repair, so eating 30 to 40 grams per meal across three or four meals tends to be more effective than loading most of your protein into a single sitting.
Why Protein Needs Increase After 50
Nearly half of all protein in the body is stored in muscle, and muscle mass naturally declines with age. This gradual loss, called sarcopenia, accelerates after 50 and can lead to weakness, falls, and loss of independence. Older adults need more protein to counteract this decline, not less.
Researchers recommend that adults over 65 consume 1.0 to 1.2 grams of protein per kilogram of body weight daily. That’s higher than the old standard recommendation and puts most older adults in the 18% to 25% range of total calories. Combined with resistance exercise, adequate protein can meaningfully slow muscle loss and help maintain strength into later decades.
Protein During Pregnancy
Protein needs rise substantially during pregnancy. The formal RDA is 1.1 grams per kilogram per day across all trimesters, but more precise research using newer methods suggests that early pregnancy (around 16 weeks) requires about 1.2 grams per kilogram, and late pregnancy (around 36 weeks) requires closer to 1.52 grams per kilogram. For a 140-pound woman, that late-pregnancy number translates to roughly 97 grams a day.
This increase supports fetal growth, placental development, and the expansion of blood volume and uterine tissue. Falling short can affect birth weight and maternal health, so this is a period where erring toward the higher end of the protein range makes sense.
Plant Protein vs. Animal Protein
Animal proteins (meat, fish, eggs, dairy) deliver all the essential amino acids your body needs in easily digestible form. They also carry nutrients like calcium and iron more efficiently. Plant proteins (beans, lentils, tofu, grains, nuts) tend to be lower in one or more essential amino acids and are generally harder for your body to break down and absorb.
For adults, these differences are manageable. Eating a variety of plant proteins throughout the day fills in the amino acid gaps. You don’t need to combine beans and rice in the same meal, just over the course of a day. That said, if you eat mostly or entirely plant-based, aiming for the higher end of the protein percentage range can compensate for the lower digestibility of plant sources.
When High Protein Becomes Too Much
For most healthy people, the practical ceiling is about 2 grams per kilogram of body weight per day. Going consistently above that level doesn’t offer clear additional benefits and does carry some risks. Very high protein diets are associated with a higher risk of kidney stones. Diets that get their protein primarily from red and processed meat also raise the risk of heart disease and colon cancer, though that’s partly about the source rather than the protein itself.
People with chronic kidney disease face a different situation entirely. Damaged kidneys struggle to filter the waste products of protein metabolism, so protein intake may need to drop to 0.55 to 0.60 grams per kilogram, well below the general population target. If you have kidney problems, your protein target is something to work out with your care team, not a general guideline.
Putting the Numbers Together
Here’s a quick reference based on goals and life stage:
- General health (most adults): 15% to 25% of calories, or 1.2 to 1.6 g/kg body weight
- Weight loss: 20% to 30% of calories
- Muscle building and athletics: 25% to 35% of calories, or 1.6 to 2.2 g/kg body weight
- Adults over 65: 1.0 to 1.2 g/kg body weight minimum
- Late pregnancy: approximately 1.5 g/kg body weight
The percentage of calories and the grams-per-kilogram number won’t always match up perfectly, because your total calorie intake shifts the math. Someone eating 1,500 calories a day hits 25% protein at 94 grams, while someone eating 3,000 calories hits it at 188 grams. Using both frameworks together gives you a more reliable target: check that your gram intake is in the right range for your body, then see what percentage that represents within your overall diet.