The short answer: cooked, skinless chicken breast contains about 165 calories, 31g protein and 3.6g fat per 100g. Raw, the same cut is only about 120 calories and 22–23g protein per 100g.
Those two sets of numbers describe the same chicken. If you have ever wondered why your tracking app gives wildly different answers for what looks like the same meal, this is why — and it is the single most common mistake people make when logging protein.
The Raw vs Cooked Mistake
Chicken loses roughly 25% of its weight during cooking. That loss is water, not protein. A 100g raw breast comes off the pan weighing around 70–75g, but it still contains exactly the same amount of protein it started with.
Cooking does not create protein or add calories. It removes water, which concentrates everything else. That is the whole explanation for why cooked chicken reads as more protein-dense per gram than raw.
The practical failure looks like this: you weigh 150g of raw chicken, cook it, and log 150g of “chicken breast” using the cooked database entry. You have just credited yourself with roughly 46g of protein when you actually ate about 35g. Repeat that daily and you are meaningfully under-eating protein while believing you are on target.
The rule: pick one state and stay consistent. Weigh raw and use raw values, or weigh cooked and use cooked values. Mixing the two is where the error lives.
Raw to Cooked Conversion Table
This is the table most chicken nutrition pages leave out. It assumes the standard ~25% cooking loss for boneless, skinless breast.
| Raw weight | Cooked weight | Calories | Protein |
|---|---|---|---|
| 100g | ~75g | ~124 | ~23g |
| 4 oz (113g) | ~3 oz (85g) | ~140 | ~26g |
| 150g | ~112g | ~185 | ~35g |
| 200g | ~150g | ~248 | ~46g |
| 8 oz (227g) | ~6 oz (170g) | ~281 | ~53g |
| 1 lb (454g) | ~12 oz (340g) | ~561 | ~105g |
Note that the calorie and protein figures are the same whichever way you measure — they describe the actual food you ate. Only the weight on the scale changes.
Cooked Chicken Breast by Serving Size
| Cooked portion | Calories | Protein | Fat |
|---|---|---|---|
| 100g | 165 | 31g | 3.6g |
| 3 oz (85g) | ~140 | ~26g | ~3.1g |
| 150g | ~248 | ~46g | ~5.4g |
| 6 oz (170g) — medium breast | ~281 | ~53g | ~6.1g |
| 8 oz (227g) — large breast | ~375 | ~70g | ~8.2g |
This is why “one chicken breast” is close to meaningless as a unit. Raw breasts commonly range from 120g to 250g depending on bird size, which means a single breast can land anywhere from roughly 140 to 375 calories. If you are tracking with any precision, weigh it.
With Skin vs Without
Roasted breast with the skin on runs around 197 calories per 100g, against 165 for skinless. Most of that difference is fat, and a meaningful share of it is saturated.
Roughly 30 extra calories per 100g is not dramatic in isolation. It matters if chicken is a daily staple and you are working within a tight calorie budget, and it matters much less than what you cook it in — a tablespoon of oil adds more than the skin does.
Does Cooking Method Change the Nutrition?
The chicken itself barely changes. What you add to it changes everything.
- Grilled, baked, roasted, poached: essentially the USDA cooked values, assuming nothing is added.
- Pan-fried in oil: add roughly 40–120 calories depending on how much oil the meat absorbs.
- Breaded and deep-fried: a different food entirely. The coating absorbs oil and can more than double the calories.
- Sauces and marinades: frequently the largest uncounted addition, especially anything sweet or creamy.
The common tracking failure here is logging “grilled chicken breast” for something that arrived breaded, sauced, or cooked in a generous amount of butter.
How Chicken Breast Compares on Protein Density
At 31g of protein for 165 calories, cooked chicken breast delivers roughly 18.8g of protein per 100 calories. That is close to the top of what any whole food achieves, and it is the reason it appears in essentially every physique and fat-loss plan.
For a real-world comparison, Chipotle’s grilled chicken sits at about 17.8g per 100 calories — nearly identical, which is a reasonable sanity check that restaurant grilled chicken is genuinely the same food and not something heavily modified.
Chicken breast is also a complete protein, supplying all nine essential amino acids, along with useful amounts of niacin, vitamin B6, phosphorus and selenium.
Practical Portioning
- General meal anchor: 100–150g cooked gives roughly 31–46g of protein, which covers most adults’ per-meal needs.
- Meal prep: buy by raw weight and multiply by 0.75 to know what you will actually end up with.
- Fat loss: chicken breast is highly satiating per calorie — pair it with vegetables for volume rather than cutting the portion.
- Don’t count the coating. Breading, sauce and frying oil are not chicken and should be logged separately.
Related reading: high-fiber foods to pair with lean protein and our Nutrition Facts Guide.
Frequently Asked Questions
How much protein is in 100g of chicken breast?
About 31g cooked, or about 22–23g raw. Both describe the same cut — the difference is water content, not protein.
Should I weigh chicken raw or cooked?
Either works, as long as you match the database entry to the state you weighed. Weighing raw is more consistent because cooking loss varies with method and time; weighing cooked is more convenient for leftovers and restaurant food.
Does cooking destroy protein in chicken?
No. Heat denatures protein — it changes its shape — but the amino acids remain available and total protein content is unchanged. Denatured protein is digested normally.
How much does one chicken breast weigh?
Raw, boneless and skinless, typically 120g to 250g. That variation is exactly why “one breast” is a poor unit for tracking.
Is chicken breast good for weight loss?
It works well for most people. High protein density supports satiety and helps preserve lean mass in a calorie deficit. It is not required — plenty of other protein sources do the same job — but it is efficient and easy to portion.
Sources
- USDA FoodData Central — chicken, broilers or fryers, breast, skinless, boneless, meat only, cooked, grilled
- USDA Food Safety and Inspection Service — Chicken from Farm to Table
Reviewed by: the HealthCoachJP Editorial Team | Last updated: July 2026 | Related: Chicken Drumstick Nutrition | Nutrition Facts Guide
Note on accuracy: values are based on USDA FoodData Central reference data and are approximate. Actual figures vary with bird size, trimming, cooking method and cooking time. Cooking loss of 25% is a standard average, not a fixed rule. This article is general information and not individual dietary advice.
