How Much Protein Do I Need a Day?

How do you calculate your protein intake?

To calculate protein intake, convert your weight to kilograms and multiply by a target in grams per kilogram (g/kg). Divide pounds by 2.2046 to get kilograms, then multiply by 0.8 for the RDA or by a higher figure if you train regularly or are older.

Worked example: a person who weighs 160 pounds weighs 72.6 kg. At the RDA of 0.8 g/kg that is 58 grams of protein a day. At 1.2 g/kg it is 87 grams, and at 1.6 g/kg it is 116 grams. For a 160-pound adult, our protein calculator returns the same 58 grams at the RDA and 87 to 145 grams across the 1.2 to 2.0 g/kg range for regular exercise.

If you prefer pounds, the RDA works out to about 0.36 grams per pound, and 1.2 to 1.6 g/kg works out to about 0.54 to 0.73 grams per pound. The per-kilogram version is what official guidance and research papers use, so it is easier to compare against sources.

How many grams of protein should you eat a day by body weight?

The table below gives daily protein in grams at five common targets. The 0.8 column is the RDA, 1.2 to 1.6 is the range in the current Dietary Guidelines, and 2.0 is the top of the range sports nutrition bodies recommend for athletes. Figures are rounded to the nearest gram, the same way our calculator rounds them.

What is the RDA for protein, and why is it only a minimum?

The Recommended Dietary Allowance (RDA) for protein is 0.8 g/kg of body weight per day for adults 19 and older, set by the National Academies of Sciences, Engineering, and Medicine. An RDA is the intake that meets the needs of nearly all healthy people in a group, so it is designed to prevent deficiency, not to maximize muscle or performance.

Using reference body weights, the National Academies express the adult RDA as 46 grams a day for women and 56 grams for men. Your own number depends on what you weigh, which is why the per-kilogram figure is more useful.

The same report sets an Acceptable Macronutrient Distribution Range (AMDR) of 10% to 35% of daily calories from protein for adults. Protein supplies 4 calories per gram, so the range in grams depends on how much you eat. For a 35-year-old woman who is 5 feet 5 inches tall, weighs 160 pounds and exercises lightly, our calculator estimates 1,955 calories a day, which puts the AMDR at 49 to 171 grams of protein.

What do the 2025–2030 Dietary Guidelines say about protein?

The 2025–2030 Dietary Guidelines for Americans, released by USDA and HHS in January 2026, advise most adults to aim for 1.2 to 1.6 grams of protein per kilogram of body weight per day and to include protein foods at every meal. That is higher than the RDA, which the National Academies have not changed.

The two figures answer different questions. The RDA is the floor that keeps nearly everyone out of deficiency; the Dietary Guidelines range is a target for an overall healthy eating pattern. For the 160-pound example, the guidelines range is 87 to 116 grams a day, compared with 58 grams at the RDA. Adjust within the range for your calorie needs and appetite.

How much protein do athletes and people who lift weights need?

People who train regularly need about 1.2 to 2.0 g/kg of protein a day, according to the 2016 joint position statement of the American College of Sports Medicine, the Academy of Nutrition and Dietetics and Dietitians of Canada. The International Society of Sports Nutrition (ISSN) gives a similar range of 1.4 to 2.0 g/kg for most exercising people.

How you spread it out also matters. The ISSN position stand suggests about 0.25 g/kg per meal, or roughly 20 to 40 grams, every three to four hours. Worked example: a 180-pound (81.6 kg) lifter aiming for 1.6 g/kg needs 131 grams a day. Split across four meals, that is about 33 grams each, comfortably above the 20-gram minimum per meal for that body weight.

Our calculator shows the 1.2 to 2.0 g/kg range for regular exercise next to the RDA, so you can see both. Start near the low end if you exercise a few times a week and move toward the high end for hard training or a calorie deficit.

How much protein do older adults need?

Adults over 65 generally benefit from 1.0 to 1.2 g/kg of protein a day, according to the PROT-AGE Study Group, an international expert panel. The group recommends 1.2 g/kg or more for older adults who exercise and about 1.2 to 1.5 g/kg for those with acute or chronic illness, because muscle mass declines with age and protein helps slow that loss.

Worked example: a 70-year-old woman who weighs 150 pounds (68.0 kg) has an RDA of 54 grams a day. At 1.0 to 1.2 g/kg her target is 68 to 82 grams. The PROT-AGE group also notes an important exception: older people with severe kidney disease who are not on dialysis may need to limit protein, so they should follow their doctor's or dietitian's advice.

How much protein do you need during pregnancy and breastfeeding?

The RDA for protein during pregnancy and breastfeeding is 71 grams a day, set by the National Academies. For pregnancy it is also expressed as 1.1 g/kg per day, with the extra protein needed mainly in the second and third trimesters to support the baby, placenta and expanded blood volume.

For a woman who weighed 150 pounds before pregnancy, 1.1 g/kg is about 75 grams, close to the flat 71-gram figure. Needs vary with body size, multiple pregnancies and medical conditions, so check targets with your obstetric care team. For dates and milestones, see our guide on how to calculate your due date.

Can you eat too much protein?

The National Academies did not set an upper limit for protein, but they cap the healthy range at 35% of calories. For most healthy adults, intakes within the ranges above are considered safe.

There are limits worth knowing. People with chronic kidney disease are often told to eat less protein, and that advice overrides any general target. Very high protein intakes can also crowd out fiber-rich foods such as vegetables, fruit, whole grains and beans. Anyone with a history of an eating disorder should set intake targets with a clinician rather than a calculator.

How does protein fit into your macros and calories?

Each gram of protein has 4 calories, so you can convert a protein target into a share of your daily calories. In the 160-pound example, 116 grams of protein supplies 464 calories, about 24% of a 1,955-calorie day, well inside the 10% to 35% AMDR.

Once protein is set, carbohydrate and fat fill the rest of your calories. Our macro calculator splits a calorie target into grams of all three, and the guide on how to calculate macros walks through the math. If you are eating less to lose weight, protein toward the upper part of your range helps preserve muscle; see how many calories to eat to lose weight.