To calculate your protein needs, multiply your body weight in kilograms by a factor that matches your activity level and goals. The baseline for healthy, sedentary adults is 0.8 grams of protein per kilogram of body weight per day, which works out to about 0.36 grams per pound. For a 150-pound person, that’s roughly 54 grams of protein daily. But that baseline is a minimum to prevent deficiency, not necessarily an optimal target, and your real number may be significantly higher depending on how active you are, how old you are, and what your body is doing right now.
The Basic Formula
Every protein recommendation starts with your weight in kilograms. If you think in pounds, divide your weight by 2.2 to convert. Then multiply that number by the grams-per-kilogram figure that fits your situation. Here’s a quick example: a 180-pound person weighs about 82 kilograms. At the baseline of 0.8 g/kg, that’s 66 grams of protein per day. At a more active target of 1.6 g/kg, it jumps to 131 grams.
The ranges below give you the multiplier to plug into that formula:
- Sedentary adults: 0.8 g/kg (the RDA minimum)
- Recreationally active adults: 1.2–1.4 g/kg
- Endurance or strength training: 1.4–2.0 g/kg
- Weight loss while preserving muscle: 1.6–2.4 g/kg
- Adults over 65: 1.0–1.2 g/kg
- Pregnancy: minimum 60 grams per day total
Protein Needs for Exercise and Muscle Building
If you exercise regularly, the standard 0.8 g/kg recommendation is too low. The International Society of Sports Nutrition’s position is that 1.4 to 2.0 g/kg per day is sufficient for most exercising people, whether the goal is building new muscle or maintaining what you have. That range covers everything from recreational gym-goers to serious athletes.
Where you land within that range depends on your training style. Endurance athletes (runners, cyclists, swimmers) generally do fine toward the lower end, around 1.4–1.6 g/kg, since their primary fuel need is carbohydrate and their protein needs center on recovery and repairing muscle damage. Resistance-trained individuals benefit from the higher end, closer to 1.6–2.0 g/kg, because strength training creates a greater demand for the raw materials that rebuild and grow muscle tissue.
There’s also evidence that going above 3.0 g/kg per day may help resistance-trained people lose fat while maintaining muscle, though that level of intake is aggressive and primarily relevant to experienced lifters with specific body composition goals.
Protein During Weight Loss
When you’re eating fewer calories than you burn, your body doesn’t just tap into fat stores. It also breaks down muscle for energy, especially if protein intake is too low. Eating more protein during a calorie deficit is one of the most effective ways to preserve lean muscle mass while losing fat.
Research on athletes cutting weight recommends 1.6 to 2.4 g/kg per day during an energy deficit. Going above about 2.4 g/kg doesn’t appear to provide additional muscle-sparing benefits. For most people trying to lose weight (not just competitive athletes), aiming for the lower end of that range, around 1.6 g/kg, is a practical and effective target. That’s double the standard RDA, but the science supports it when calories are restricted.
To put this in real numbers: a 160-pound person (73 kg) cutting calories would aim for roughly 117 to 175 grams of protein per day. Spreading that across three or four meals tends to work better for appetite control and muscle protein synthesis than loading it all into one or two sittings.
Why Protein Needs Increase After 65
Aging muscles become less responsive to protein. The same meal that triggers robust muscle repair in a 30-year-old produces a weaker response in a 70-year-old, a phenomenon researchers call “anabolic resistance.” Over years, this contributes to sarcopenia, the gradual loss of muscle mass and strength that accelerates falls, fractures, and loss of independence.
To counteract this, experts recommend that adults over 65 consume 1.0 to 1.2 grams of protein per kilogram of body weight daily. That’s 25 to 50 percent more than the standard RDA. For a 140-pound older adult (64 kg), that means 64 to 77 grams per day rather than the 51 grams the baseline formula would suggest. The difference may not sound dramatic, but sustained over months and years it meaningfully affects muscle retention.
Protein During Pregnancy
Pregnancy increases protein requirements to support fetal growth, placental development, and expanded blood volume. The general recommendation is a minimum of 60 grams of protein per day, which should account for roughly 20 to 25 percent of total calorie intake. Many women already meet or exceed this if they eat a varied diet, but it’s worth tracking for a few days if you’re unsure, especially during the second and third trimesters when fetal growth accelerates.
Is Too Much Protein Dangerous?
For healthy people, high-protein diets are not known to cause medical problems. The old concern that excess protein damages kidneys has not held up in studies of people with normal kidney function. Your kidneys are well equipped to handle the extra waste products that come from breaking down protein.
The exception is people who already have kidney disease. In that case, a high protein intake can worsen kidney function because the organs struggle to clear the byproducts efficiently. The same caution applies if you have diabetes, which can affect kidney health over time. If either applies to you, working with a provider to set a protein target is important.
Putting Your Number Into Practice
Once you’ve calculated your daily target, the next question is how to actually hit it. A palm-sized portion of chicken, fish, or meat contains roughly 25 to 30 grams of protein. A cup of Greek yogurt has about 15 to 20 grams. Two eggs provide around 12 grams. A cup of cooked lentils delivers about 18 grams. These rough benchmarks make it easier to assemble meals without weighing everything.
Protein is also more satiating than carbohydrate or fat, gram for gram, which is why higher-protein diets tend to reduce overall hunger. If you’re increasing your intake substantially, ramping up over a week or two gives your digestion time to adjust. Some people notice bloating or digestive discomfort when they jump from 60 grams to 150 grams overnight.
Your ideal number isn’t static. It shifts as your goals, activity level, and life stage change. Recalculating every few months, or whenever your routine changes significantly, keeps your intake matched to what your body actually needs.