A cooked, skinless, boneless chicken breast contains about 165 calories and 31 grams of protein per 100 grams. A typical whole breast from the grocery store weighs around 170 to 175 grams after cooking, which puts a single breast at roughly 280 calories and 54 to 56 grams of protein. Those numbers make chicken breast one of the leanest, most protein-dense foods available.
Calories and Protein Per Serving Size
Because chicken breasts vary in size, it helps to know the numbers at a few common serving sizes. All figures below are for cooked, skinless, boneless breast.
- 100 grams (3.5 oz): 165 calories, 31 g protein, 3.6 g fat
- 6 ounces (170 g): ~280 calories, ~53 g protein, ~6 g fat
- One whole breast (~174 g): ~284 calories, 56 g protein
Raw chicken breast starts at about 112 calories per 100 grams. Cooking drives off water, concentrating the nutrients into a smaller weight. That’s why the cooked number is higher: you’re not adding calories, you’re just left with less water weight per serving. If you’re tracking food with a kitchen scale, weigh your chicken after cooking and use the 165 calories per 100 grams figure.
How Skin and Cooking Method Change the Numbers
Leaving the skin on adds a noticeable amount of fat and calories. A 3.5-ounce serving of cooked chicken breast with skin contains 197 calories and 7.8 grams of fat, compared to 165 calories and 3.6 grams of fat without. That’s roughly a 20% calorie increase, with the fat content more than doubling. Protein drops slightly because the skin contributes weight but little protein.
Cooking method matters even more than skin. Grilling, roasting, baking, or poaching a skinless breast all land near that 165-calorie baseline. Breading and frying is a different story entirely. A 100-gram portion of extra crispy fried chicken breast (with skin and breading) jumps to 268 calories and 16.6 grams of fat. That’s over 60% more calories and nearly five times the fat of a plain roasted breast. If you’re eating chicken breast specifically because it’s lean, how you prepare it is just as important as the cut you choose.
Why Chicken Breast Protein Stands Out
Roughly 80% of the calories in a skinless chicken breast come from protein, with the remaining 20% from fat. Very few whole foods hit that ratio. Chicken breast protein is also complete, meaning it provides all the essential amino acids your body needs, including leucine, the amino acid most directly involved in triggering muscle repair and growth.
Protein also has a high thermic effect, meaning your body uses more energy to digest it than it does for fat or carbohydrates. About 25% of protein calories are burned during digestion, compared to roughly 7.5% for carbs and just 1.5% for fat. In practical terms, a 200-calorie portion of raw chicken breast (about 39 grams of protein and 5 grams of fat) yields closer to 161 usable calories after digestion. This doesn’t mean you should adjust your calorie tracking, but it does help explain why high-protein diets tend to support fat loss: your body works harder to process the food, and protein keeps you feeling full longer.
Chicken Breast vs. Chicken Thighs
Chicken thighs are the most common alternative, and the difference is meaningful if you’re watching your macros. Per 100 grams of cooked, skinless meat, thighs contain about 25 grams of protein and 176 calories, compared to 31 grams of protein and 166 calories for breast. That gap of 6 grams of protein per 100 grams adds up over a day, especially if chicken is your primary protein source. Thighs carry more fat, which accounts for the extra calories despite having less protein. They’re not a bad choice by any means, just a fattier, slightly less protein-efficient one.
Vitamins and Minerals Worth Noting
Chicken breast is often discussed purely in terms of protein and calories, but a 6-ounce serving delivers a surprisingly strong micronutrient profile. It covers nearly 100% of the daily value for niacin (vitamin B3), which plays a central role in converting food into energy. The same serving provides 92% of the daily value for vitamin B6, important for immune function and brain health, and 99% of the daily value for selenium, a mineral that supports thyroid function and acts as an antioxidant. You also get about a third of your daily phosphorus, which your body uses to build and maintain bones.
Organic vs. Conventional Chicken
If you’re wondering whether organic chicken breast has more protein or fewer calories, the short answer is no. The USDA defines organic poultry by how it’s raised, handled, and processed, not by differences in safety or nutritional content. Many people assume organic means more nutritious, but the protein, fat, and calorie content of a chicken breast is essentially the same regardless of how the bird was raised. You may have other reasons for choosing organic, like animal welfare or environmental concerns, but the macros on your plate won’t change.