A skinless chicken breast has about 6.4 grams of protein per raw ounce and about 8.8 grams per cooked ounce. It's the same meat with less water in it. Cooking doesn't add protein. It removes water, so each ounce left on the plate holds more of what was already there.
That one fact explains most of the confusion about chicken breast protein. Two people can weigh the same breast, quote numbers about a third apart, and both be right. The rest of this page is the arithmetic, the ranked tables, and the one question to ask before you trust any protein figure: raw or cooked?
How much protein is in a chicken breast?
The working numbers come from USDA FoodData Central, the federal nutrient database. Two entries matter here: "Chicken, broilers or fryers, breast, meat only, raw" and "Chicken, broilers or fryers, breast, meat only, cooked, roasted." Meat only means skinless and boneless, which is how most people buy breast now.
- Raw: about 22.5 g of protein and 120 calories per 100 g.
- Roasted: about 31 g of protein and 165 calories per 100 g.
Raw weight is what the meat weighs before it goes near heat, straight out of the package. Cooked weight is what the same piece weighs after cooking, once the water has left.
A package label, a meal-prep recipe and most nutrition apps use raw weight. A restaurant portion and the chicken on your plate are cooked weight.
How much protein is in one whole breast?
A "chicken breast" from a US grocery store is usually 6 to 8 oz raw, though some run larger. At 22.5 g per 100 g raw, one breast gives roughly 38 to 51 g of protein.
That's a wide range for something sold as one unit. The size of the breast moves the total more than anything else on this page.
A note on the figures
FoodData Central entries get revised, and different datasets in the database list slightly different values for the same cut. The figures here match the long-standing reference entries for raw and roasted breast.
If you plan to reuse them, pull both entries yourself and check that the values haven't moved. A change of half a gram per 100 g would shift every row in the tables below by a fraction of a gram, and nothing a kitchen scale could see.
Breast meat is close to the most predictable protein in the grocery store. Per 100 g, it barely varies between brands. The number isn't the confusing part. The scale is.
Chicken breast protein per ounce: raw and cooked
This is the table worth saving. Every cell is arithmetic from the two FoodData Central entries above, using 28.35 g per ounce.
Per ounce, 1 to 8 oz
| Weight | Raw protein (g) | Raw calories | Cooked protein (g) | Cooked calories | Protein per 100 kcal (g) |
|---|---|---|---|---|---|
| 1 oz | 6.4 | 34 | 8.8 | 47 | 18.8 |
| 2 oz | 12.8 | 68 | 17.6 | 94 | 18.8 |
| 3 oz | 19.1 | 102 | 26.4 | 140 | 18.8 |
| 4 oz | 25.5 | 136 | 35.2 | 187 | 18.8 |
| 5 oz | 31.9 | 170 | 43.9 | 234 | 18.8 |
| 6 oz | 38.3 | 204 | 52.7 | 281 | 18.8 |
| 7 oz | 44.7 | 238 | 61.5 | 327 | 18.8 |
| 8 oz | 51.0 | 272 | 70.3 | 374 | 18.8 |
Source: USDA FoodData Central, chicken breast, meat only, raw (22.5 g protein, 120 kcal per 100 g) and roasted (31 g protein, 165 kcal per 100 g). Protein is rounded to one decimal and calories to the nearest whole number, so a row may differ from your own math by 0.1 g or 1 kcal. The ratio column is 18.75 raw and 18.79 cooked, both shown as 18.8.
Read across any row and the trap is visible. Four ounces raw is 25.5 g. Four ounces cooked is 35.2 g.
Same label on the row, different chicken. Four ounces of cooked meat started life as about 5.5 oz of raw meat.
Why the ratio does not change
Look at the last column. It doesn't move. Raw or cooked, chicken breast gives about 18.8 g of protein for every 100 calories.
The reason is water. Cooking drives water out of the meat, and water has no protein and no calories. Take it away and the protein and the calories concentrate together, at the same rate, so the ratio between them stays put.
Per ounce, everything goes up. Per calorie, nothing changes.
The ratio is the honest number. The weight is the variable.
Why does 4 oz raw become about 3 oz cooked?
Because roughly a quarter of a chicken breast's weight is water that leaves in the pan. This is the single biggest source of disagreement about chicken protein, and it has nothing to do with the chicken.
Water loss, roughly a quarter of the weight
Raw chicken breast is about 75 percent water. As it cooks, muscle fibers tighten and push some of that water out, along with a small amount of fat.
The fraction of the raw weight that's left after cooking is called the yield. A yield of 75 percent means 100 g raw becomes 75 g cooked.
The two FoodData Central entries imply a yield of about 73 percent for roasted breast: 22.5 g of protein per 100 g raw divided by 31 g per 100 g cooked. In a home kitchen, the yield usually lands somewhere around 70 to 80 percent.
Poaching tends to keep more water in. A long, hot grill takes more out. A thin cutlet cooked past done can drop below 70. So 0.75 is a working figure, not a constant, and the real number on any given night depends on the method and the minutes.
A conversion you can check
The rule: multiply raw weight by 0.75 to get cooked weight. Divide cooked weight by 0.75 to get raw weight.
- 4 oz raw becomes about 3 oz cooked
- 6 oz raw becomes about 4.5 oz cooked
- 8 oz raw becomes about 6 oz cooked
Now check it against the table. Four ounces raw is 25.5 g of protein. Three ounces cooked is 26.4 g.
That's the same piece of chicken, counted two ways. The 0.9 g gap is rounding plus the fact that the database's roasted entry implies a slightly lower yield than 0.75. The protein didn't go anywhere. The scale just read a smaller number.
The same works in reverse. If a restaurant serves 6 oz of grilled breast, that plate started at about 8 oz raw, which is about 51 g of protein. Use the cooked column and you get 52.7 g. Same answer, give or take a gram.
The same chicken has two weights, and the internet tends to quote whichever one made the number bigger.
How much protein is in 4, 6 and 8 oz of chicken breast?
With the conversion settled, here are the three portions people ask about most, each in both states.
4 oz
Four ounces of chicken breast has about 25.5 g of protein raw (136 calories) or about 35 g cooked (187 calories).
6 oz
Six ounces of chicken breast has about 38 g of protein raw (204 calories) or about 53 g cooked (281 calories).
8 oz
Eight ounces of chicken breast has about 51 g of protein raw (272 calories) or about 70 g cooked (374 calories).
The common mistake: mixing the two
A recipe that says "6 oz chicken" almost always means raw weight, because that's what you measure before you cook. A menu that lists "6 oz grilled chicken" may mean either. A plate weighed at the table is always cooked.
Read a cooked portion against the raw column and you undercount by about a quarter. Read a raw portion against the cooked column and you overcount by more than a third.
As plain arithmetic, per meal: a 4 oz raw portion gives about 25 g of protein, and a 6 oz raw portion gives about 38 g. That's what the scale and the database say. What any of those amounts does in a body is a separate question, and this page doesn't answer it.
Weigh it once, in one state, and use the matching column.
How does chicken breast rank per 100 calories?
Grams per serving tells you how much protein is on the plate. Grams per 100 calories tells you how much protein each calorie carries. The second number is the one that lets you compare foods of different sizes fairly.
A ranked table, per 100 calories and per 100 g
| Food | Calories per 100 g | Protein per 100 g (g) | Protein per 100 kcal (g) |
|---|---|---|---|
| Egg white, raw | 52 | 10.9 | 21.0 |
| Whey protein powder (representative label: about 120 kcal for 24 to 25 g) | varies by label | about 75 to 85 | about 20 |
| Chicken breast, meat only, roasted | 165 | 31.0 | 18.8 |
| Greek yogurt, plain, nonfat | 59 | 10.2 | 17.3 |
| Protein bar (representative label: about 200 kcal for 20 g) | varies by label | about 30 to 35 | about 10 |
| Whole egg, raw | 143 | 12.6 | 8.8 |
| Lentils, boiled | 116 | 9.0 | 7.8 |
Source: whole-food rows from USDA FoodData Central; powder and bar rows are representative label ranges for the category, not any one product.
Chicken breast sits near the top, a little behind egg white and roughly level with a typical whey powder. Greek yogurt is close behind. Bars, whole eggs and lentils carry more of their calories as fat or carbohydrate, so the ratio is lower.
Every food on this list is a fine answer. The table states a ratio. It doesn't rank foods as better or worse.
What "high protein" means on a label
"High protein" is a regulatory term, not a description. Under US food labeling rules, a product may say "high in protein" or "excellent source of protein" only when one serving provides at least 20 percent of the Daily Value. Against the 50 g Daily Value for protein, that's 10 g per serving.
The percentage is calculated after a quality correction called PDCAAS, a score for how well a protein covers the essential amino acids, adjusted for digestibility. "Essential" here means the body cannot make them and has to get them from food, not "important."
By that definition, a 4 oz raw portion of chicken breast, a typical scoop of whey and a typical bar all qualify. The phrase describes grams per serving. It says nothing about grams per calorie.
What the ratio hides
The ratio is one number. It doesn't capture fiber, which lentils have and chicken doesn't. It doesn't capture the fats and micronutrients in a whole egg, the calcium in yogurt, the price per gram, or how long a food keeps in a bag.
It also ignores convenience, which for someone who skips lunch is often the deciding factor. Packaged protein has one practical advantage here: the grams are already counted and the dose is the same every day, with no scale and no yield to guess.
Use the ratio to compare. Use everything else to choose.
What changes the protein number on your plate?
The tables assume skinless breast, cooked plain. Real meals drift from that in a few predictable ways.
Skin, cut and cooking method
Skin is mostly fat. Leave it on and the calories per ounce go up faster than the protein, so the ratio drops. Roasted breast with skin works out to roughly 15 g of protein per 100 calories in the FoodData Central reference values, against 18.8 g without it.
Skinless thigh lands lower still, around 14 to 16 g per 100 calories depending on whether you use the raw or roasted entry, because thigh carries more fat. It's still a good source of protein. The ratio is just different.
Marinades, breading, butter and cooking oil add calories and add no meaningful protein. A tablespoon of olive oil is about 120 calories. Brush that over a 6 oz breast and the plate's ratio falls from about 19 g to about 12 g per 100 calories, even though the chicken itself didn't change.
A package label that says "serving" almost always means raw, and it never means the oil.
Cooking also denatures the protein, which means heat unfolds its shape. That changes texture and makes the meat firm. Denatured protein keeps its amino acids, so cooking changes the weight and the feel of the meat, not the protein count in the piece.
Breast meat is not uniform
Commercial broiler breast varies more than the database row suggests. Two myopathies, meaning muscle disorders, come up in poultry research. Wooden breast makes the meat unusually hard and changes its texture. White striping shows up as white streaks of fat running along the muscle fibers.
A 2025 study found these myopathies often occur together and affect carcass and meat quality traits (Muñoz-Lapeira et al., 2025). A separate study ran cooked wooden breast meat through an in vitro digestion, meaning a simulated digestion in lab glassware rather than in people, and reported differences in protein digestibility compared with normal meat (Trithavisup et al., 2024).
Read those for what they are. They describe texture, composition and a lab model. Neither tests what happens in a person, and neither changes the per-ounce table in any way a kitchen scale would show.
Interesting for poultry scientists. Not a reason to re-weigh dinner.
Read the denominator before you read the number
Every protein figure is a fraction. The protein is the top number. The denominator is the thing it's divided by: a serving, an ounce, 100 grams, 100 calories. Change the denominator and the same food looks different.
Raw or cooked, per serving or per 100 g
A package that says 27 g of protein per 4 oz (113 g) raw describes the same chicken as a nutrition app that says 26 g per 3 oz (85 g) cooked. Neither is wrong. They're divided by different things.
Before you compare two figures, check two details. Is the weight raw or cooked? Is the denominator a serving, a weight or a calorie count?
A before-and-after of one label line
- As printed: Serving 4 oz (113 g) raw, 130 calories, 27 g protein.
- Per 100 g: 27 divided by 1.13 is 23.9 g protein, and 130 divided by 1.13 is 115 calories.
- Per 100 kcal: 27 divided by 1.3 is 20.8 g protein.
That's a little above the database's 18.8 g, which is normal. Labels round calories to the nearest 10 and protein to the nearest gram, and that alone can move a ratio by a gram or two. The ballpark is what matters, and it matches.
So: check whether the weight is raw or cooked, use the matching column in the table, and compare foods on grams per 100 calories when calories are the constraint. A packaged protein with the grams printed on the front and a food scale on the counter answer the same question. Neither has to be the only answer.
The short version
Skinless chicken breast has about 6.4 g of protein per raw ounce and about 8.8 g per cooked ounce. The difference is water, not protein. Cooking removes roughly a quarter of the weight, so 4 oz raw becomes about 3 oz cooked, and the protein in that piece stays the same.
By raw weight, 4 oz of chicken breast is about 25 g of protein, 6 oz is about 38 g, and 8 oz is about 51 g. By cooked weight, the same three portions are about 35 g, 53 g and 70 g. A typical store-bought breast of 6 to 8 oz raw lands between 38 and 51 g.
Per calorie, the number holds still: about 18.8 g of protein per 100 calories, raw or cooked. That puts chicken breast near egg white and a typical whey powder, and ahead of whole eggs, bars and lentils on that one measure. Every figure here comes from USDA FoodData Central or is arithmetic you can redo from it.
Know which weight you're holding. The rest is division.
Frequently Asked Questions
How much protein is in 4 oz of chicken breast?
Four ounces of skinless chicken breast has about 25.5 g of protein raw (136 calories) or about 35 g cooked (187 calories). The cooked figure is higher per ounce because cooking removes water, not because protein is added.
Does cooking chicken breast increase its protein?
No. Cooking removes roughly a quarter of the meat's weight as water, so each cooked ounce holds more protein (about 8.8 g versus 6.4 g raw), but the total protein in the piece stays the same.
How much protein is in one whole chicken breast?
A typical US grocery store chicken breast weighs 6 to 8 oz raw and contains roughly 38 to 51 g of protein. The size of the breast changes the total more than any other factor.
How do you convert raw chicken weight to cooked weight?
Multiply raw weight by 0.75 to estimate cooked weight, or divide cooked weight by 0.75 to estimate raw weight, so 4 oz raw becomes about 3 oz cooked. Actual yield usually falls between 70 and 80 percent, depending on cooking method and time.
How much protein does chicken breast have per 100 calories?
Skinless chicken breast has about 18.8 g of protein per 100 calories, raw or cooked, based on values from USDA FoodData Central. The ratio stays the same because the water lost in cooking contains neither protein nor calories.
Is the protein on a chicken package label for raw or cooked weight?
Package labels and most recipes almost always use raw weight, while restaurant portions and food weighed on the plate are cooked weight. Reading a cooked portion against raw values undercounts protein by about a quarter, and reading a raw portion against cooked values overcounts by more than a third.