Your protein needs depend on your body weight, activity level, age, and goals. The baseline recommendation for all adults is 0.8 grams of protein per kilogram of body weight per day. For a 150-pound person (68 kg), that works out to about 54 grams. But that number is a minimum to prevent deficiency, not necessarily an optimal target, and most people benefit from more.
To find your number, you’ll multiply your weight in kilograms by a factor that matches your situation. One kilogram equals about 2.2 pounds, so divide your weight in pounds by 2.2 first.
The Baseline: 0.8 Grams Per Kilogram
The international Recommended Dietary Allowance sets protein at 0.8 g/kg/day for all adults regardless of age. This is the amount needed to meet basic nutritional needs and maintain nitrogen balance in a sedentary, healthy adult. It’s a floor, not a ceiling. If you don’t exercise regularly, aren’t trying to lose weight, and are under 65, this number is a reasonable starting point. For a 180-pound person, that’s roughly 65 grams per day.
If You Exercise Regularly
Physical activity increases protein needs substantially. The International Society of Sports Nutrition recommends 1.4 to 2.0 g/kg/day for most exercising individuals looking to build or maintain muscle. For that same 180-pound person, that range jumps to about 115 to 164 grams per day.
Where you fall within that range depends on intensity. If you lift weights a few times a week, aiming for the middle (around 1.6 g/kg) covers most people well. If you’re doing serious strength or power training and trying to maximize muscle growth, pushing toward 2.0 g/kg makes sense. Endurance athletes, such as distance runners and cyclists, need about 1.8 g/kg on standard training days and closer to 2.0 g/kg during heavy training blocks or recovery days.
If you’re actively cutting calories while trying to hold onto muscle, protein needs go even higher. Resistance-trained people in a calorie deficit may need 2.3 to 3.1 g/kg/day to minimize muscle loss. That’s a lot of protein, but the logic is straightforward: when your body has fewer calories to work with, it’s more likely to break down muscle for energy unless you give it plenty of amino acids.
If You’re Trying to Lose Weight
Protein is your best tool for preserving muscle during weight loss. A meta-analysis of 30 studies found that people with overweight or obesity who ate more than 1.3 g/kg/day while dieting actually gained muscle mass, while those eating less than 1.0 g/kg/day were at higher risk of losing it. That’s a meaningful threshold to remember: staying above 1.3 g/kg helps protect the muscle you already have.
Protein also helps with satiety. It keeps you fuller longer than the same number of calories from carbohydrates or fat, which makes sticking to a calorie deficit easier in practice. For weight loss, a target of 1.2 to 1.6 g/kg is a practical range for most people.
If You’re Over 65
Aging muscles become less responsive to protein. Nearly half the protein in your body is stored in muscle tissue, and muscle mass naturally declines with age, a process called sarcopenia. To counteract this, researchers recommend older adults consume 1.0 to 1.2 g/kg/day, a 25 to 50 percent increase over the standard RDA.
Meal distribution matters more as you age, too. Older adults appear to need about 25 to 30 grams of protein per meal to trigger the muscle-building response effectively. Spreading protein across three meals rather than loading it all into dinner can make a real difference in maintaining strength and function.
During Pregnancy and Breastfeeding
Protein needs rise during pregnancy, but the increase is modest in the first trimester (only about 1 extra gram per day). By the second trimester, that climbs to roughly 9 additional grams per day, and by the third trimester, you need about 28 to 31 extra grams daily on top of your normal intake. During breastfeeding, the additional requirement is around 19 grams per day for the first six months, dropping to about 13 grams after that as breastfeeding becomes partial.
What to Do If You Carry Extra Body Fat
Standard protein calculations use total body weight, which can overestimate needs for someone carrying a significant amount of body fat. Fat tissue doesn’t require much protein to maintain. If your body fat percentage is above 30 percent (for men) or above 40 percent (for women), calculating protein based on your goal weight or lean body mass gives a more accurate target. A simple approach: use your goal weight instead of your current weight in the calculation, then apply the multiplier that matches your activity level.
Plant Protein vs. Animal Protein
Plant proteins are generally less digestible and often lack one or more essential amino acids compared to animal sources. Lysine, for example, is low in many grain-based proteins. This doesn’t mean plant-based diets can’t meet protein needs, but it does mean you may need to eat a bit more total protein and combine different sources (legumes with grains, for instance) to get a complete amino acid profile. For adults, these differences are manageable. For children and infants, the gap in protein quality matters more because of their developmental demands.
Is High Protein Safe for Your Kidneys?
This concern comes up often, and the short answer for healthy people is reassuring. Clinical trials lasting six months or longer have generally shown little to no effect on kidney function from high-protein diets. A large observational study of women found that increased protein intake was associated with declining kidney function only in those who already had mild kidney problems, not in women with healthy kidneys. If you have existing kidney disease, protein intake is something to manage carefully with a healthcare provider. For everyone else, intakes up to 2.0 g/kg/day and even higher have not been shown to cause kidney damage.
A Quick Reference by Situation
- Sedentary adult under 65: 0.8 g/kg/day
- Adult over 65: 1.0 to 1.2 g/kg/day
- Weight loss: 1.2 to 1.6 g/kg/day (above 1.3 to protect muscle)
- Regular exercise: 1.4 to 2.0 g/kg/day
- Intense training in a calorie deficit: 2.3 to 3.1 g/kg/day
- Third trimester of pregnancy: baseline plus 28 to 31 g/day
- Breastfeeding (first 6 months): baseline plus 19 g/day
To calculate yours: take your weight in pounds, divide by 2.2 to get kilograms, then multiply by the number that fits your life. A 160-pound person who exercises regularly, for example, weighs about 73 kg. At 1.6 g/kg, that’s roughly 117 grams of protein per day. That could look like three eggs at breakfast, a chicken breast at lunch, Greek yogurt as a snack, and a salmon fillet at dinner.