To calculate how much protein you need each day, multiply your body weight in kilograms by a factor that matches your activity level and life stage. The baseline is 0.8 grams per kilogram of body weight (or 0.36 grams per pound) for sedentary adults, but most active people need significantly more. The 2025-2030 Dietary Guidelines for Americans now suggest 1.2 to 1.6 grams per kilogram for most adults.
The Basic Formula
The math is straightforward. First, convert your weight to kilograms by dividing your weight in pounds by 2.2. Then multiply that number by your protein factor. For a 160-pound person, that looks like this:
- Sedentary adult (0.8 g/kg): 160 ÷ 2.2 = 72.7 kg × 0.8 = about 58 grams per day
- Moderately active adult (1.2 g/kg): 72.7 kg × 1.2 = about 87 grams per day
- Very active adult (1.6 g/kg): 72.7 kg × 1.6 = about 116 grams per day
If you prefer working in pounds, you can skip the conversion and multiply your weight by 0.36 (sedentary minimum), 0.55 (moderately active), or 0.73 (very active) to get roughly the same numbers.
How Activity Level Changes Your Number
The 0.8 g/kg baseline is a minimum to prevent deficiency in people who don’t exercise regularly. It’s not a target for anyone trying to build or maintain muscle. If you exercise a few times a week, whether that’s jogging, cycling, or group fitness classes, your needs rise to about 1.1 to 1.5 grams per kilogram.
People who regularly lift weights or train for endurance events like marathons or long cycling races need 1.2 to 1.7 grams per kilogram. Intakes above 2 grams per kilogram per day are generally considered excessive, with diminishing returns for muscle building and potential downsides for kidney health over time.
Adjustments for Age
Muscle mass naturally declines with age, a process called sarcopenia. Nearly half of all protein in the body is stored in muscle, so this gradual loss makes adequate protein intake increasingly important as you get older. The official RDA stays the same at 0.8 g/kg for all adults over 19, but most researchers who study aging now recommend that adults over 65 aim for 1.0 to 1.2 grams per kilogram daily. Some evidence suggests going up to 1.6 g/kg may help older adults increase muscle strength, particularly if they’re also doing resistance exercise. For a 180-pound older adult, that range translates to roughly 82 to 130 grams per day.
Adjustments for Pregnancy
Protein needs increase during pregnancy, but not as dramatically in the first trimester as many people assume. In the first trimester, you only need about 1 extra gram of protein per day beyond your normal intake. That jumps to roughly 9 additional grams per day in the second trimester and 28 to 31 additional grams per day in the third trimester, when fetal growth accelerates. If your pre-pregnancy intake was around 50 grams a day, you’d want to be eating close to 80 grams daily by late pregnancy.
Protein During Weight Loss
When you’re eating fewer calories than you burn, your body can break down muscle for energy unless you give it enough protein to protect that tissue. This is why protein becomes more important during a caloric deficit, not less. Aiming for the higher end of the recommended range, around 1.2 to 1.6 g/kg, helps preserve lean muscle mass while you lose fat. Pairing higher protein intake with resistance training makes this effect even stronger.
Should You Calculate From Total Weight or Lean Mass?
Most guidelines use total body weight because it’s simple and doesn’t require any special measurements. This works well for people at a moderate body fat percentage. If you carry a significant amount of extra body fat, though, calculating from total weight can overestimate your needs since fat tissue doesn’t require protein the way muscle does. In that case, using an adjusted body weight or your goal weight as the basis for the calculation gives a more practical number. For example, if you weigh 250 pounds but your goal weight is 180, multiplying 180 by your per-pound protein factor will give you a more useful daily target.
How to Spread Protein Across the Day
Your body can only use so much protein at once for building and repairing muscle. Research suggests that 20 to 25 grams of protein per meal is the threshold that triggers the strongest muscle-building response in younger adults. Eating significantly more than that in a single sitting doesn’t go to waste (your body still uses it for energy and other functions), but it doesn’t proportionally increase muscle repair.
The practical takeaway: spread your daily target across at least three to four meals rather than loading it all into dinner. If your goal is 120 grams, aiming for 30 grams at each of four meals is more effective than eating 20 grams at breakfast, 20 at lunch, and 80 at dinner. The research-supported range is 0.4 to 0.55 grams per kilogram per meal, spread across four eating occasions.
When High Protein Becomes a Concern
Processing protein creates more waste products that your kidneys need to filter out, so very high intakes create extra workload for those organs. For people with healthy kidneys, this generally isn’t a problem at recommended levels. But if you have any degree of kidney disease, even the higher end of normal recommendations could be too much. Staying at the lower end of the range, or below it, is safer in that situation.
The source of your protein matters here too. Animal proteins like meat tend to produce more acid for your kidneys to clear, while plant-based proteins are generally easier on the kidneys. Some research has also linked sustained intakes above 2 g/kg per day to an increased risk of chronic disease over time, so there’s no benefit to going as high as possible. More is not always better.
Quick Reference by Category
- Sedentary adult: 0.8 g/kg (0.36 g/lb)
- Recreationally active: 1.1–1.5 g/kg (0.5–0.68 g/lb)
- Strength training or endurance sports: 1.2–1.7 g/kg (0.55–0.77 g/lb)
- Adults over 65: 1.0–1.2 g/kg (0.45–0.55 g/lb), up to 1.6 g/kg with strength training
- During weight loss: 1.2–1.6 g/kg (0.55–0.73 g/lb)
- Third trimester of pregnancy: normal intake plus 28–31 g/day
- Upper boundary for most people: 2.0 g/kg (0.9 g/lb)
Pick the category that fits your situation, do the multiplication, and divide the result by the number of meals you eat each day. That’s your per-meal protein target.