How is cooking yield calculated?

Protein mass is approximately conserved during cooking. If raw food has P_raw grams of protein per 100g and cooked has P_cooked, then 100g raw produces 100 × P_raw / P_cooked grams of cooked food. Values are derived from USDA FoodData Central raw-and-cooked pairs.

Cooking Yield Calculator

Q: How much does 100g of raw chicken breast weigh cooked?

About 70g. Raw chicken breast has 22.5g protein per 100g and cooked has 32.1g per 100g; since protein is conserved during cooking, 100g raw yields roughly 100 × 22.5 / 32.1 ≈ 70g cooked. The 30g difference is evaporated water.

Q: Does cooked chicken have more protein than raw?

No — not per original gram of meat. Cooked chicken shows more protein per 100g only because water evaporated, concentrating the same protein into less weight. The total protein in your portion is the same whether you weigh it raw or cooked.

Convert raw weight to cooked (and back) for 33 common foods

100g of raw chicken breast cooks down to about 70g because water evaporates. 100g of dry lentils expands to about 275g boiled because they absorb water. These yields are derived from USDA FoodData Central raw and cooked protein values, using the principle that protein mass is conserved during cooking.

Food

Direction

Raw Weight (grams)

Result

70g cooked

100g raw chicken breast → ~70g cooked, containing 22.5g protein.

Cooking concentrates protein as water evaporates, so cooked weight is lower.

Full Cooking Yield Reference

Every food with raw and cooked USDA data, showing the expected yield in both directions. All values per 100g starting weight.

Cooking yield reference: raw to cooked and cooked to raw weight conversion for 33 USDA foods.
Food	Method	100g raw →	100g cooked ←	Category
Amaranth Grain	cooked	357g	28g	Cereal Grains and Pasta
Beef liver	fried	77g	130g	Beef Products
Beef sirloin	grilled	76g	132g	Beef Products
Black beans	boiled	275g	36g	Legumes and Legume Products
Broccoli	boiled	118g	84g	Vegetables and Vegetable Products
Brown rice	cooked	275g	36g	Cereal Grains and Pasta
Bulgur	cooked	399g	25g	Cereal Grains and Pasta
Chicken breast	cooked	70g	143g	Poultry Products
Chicken liver	fried	66g	152g	Poultry Products
Chicken thigh	cooked	76g	132g	Poultry Products
Chickpeas	boiled	240g	42g	Legumes and Legume Products
Couscous	cooked	337g	30g	Cereal Grains and Pasta
Crab	cooked	101g	99g	Finfish and Shellfish Products
Egg	fried	92g	108g	Dairy and Egg Products
Eggplant	boiled	118g	85g	Vegetables and Vegetable Products
Fresh tuna	cooked	78g	128g	Finfish and Shellfish Products
Green beans	microwaved	85g	117g	Vegetables and Vegetable Products
Green peas	boiled	101g	99g	Vegetables and Vegetable Products
Halibut	cooked	82g	121g	Finfish and Shellfish Products
Lentils	boiled	273g	37g	Legumes and Legume Products
Mackerel	cooked	78g	128g	Finfish and Shellfish Products
Mussel	cooked	50g	200g	Finfish and Shellfish Products
Oat Bran	cooked	539g	19g	Cereal Grains and Pasta
Oyster	cooked	50g	200g	Finfish and Shellfish Products
Pork liver	cooked	82g	122g	Pork Products
Quinoa	cooked	321g	31g	Cereal Grains and Pasta
Salmon	cooked	92g	109g	Finfish and Shellfish Products
Scallop	steamed	59g	170g	Finfish and Shellfish Products
Shrimp	cooked	65g	154g	Finfish and Shellfish Products
Split peas	boiled	277g	36g	Legumes and Legume Products
Tilapia	cooked	73g	138g	Finfish and Shellfish Products
Trout	cooked	89g	112g	Finfish and Shellfish Products
Turkey liver	cooked	68g	148g	Poultry Products

Method: Protein mass is approximately conserved during cooking, so cooked weight = 100 × (raw protein density) / (cooked protein density). Source: USDA FoodData Central. Values are approximations; actual yield varies with cooking method, time, and starting moisture.

Common Questions

How much does 100g of raw chicken breast weigh cooked?

About 70g. Raw chicken breast has 22.5g protein per 100g; cooked has 32.1g per 100g. Since protein is conserved during cooking, 100g raw yields roughly 100 × 22.5 / 32.1 ≈ 70g cooked. The ~30g difference is evaporated water.

Why does 100g of dry lentils weigh more after boiling?

Dry lentils absorb water when boiled. 100g dry lentils (24.6g protein) becomes roughly 275g boiled lentils (9.0g protein per 100g). The total protein is the same — the weight just triples from water absorption.

Does cooked chicken have more protein than raw?

Not per original gram of meat. Cooked chicken shows more protein per 100g only because water evaporated, concentrating the same protein into less weight. The total protein in your portion is the same whether you weigh it raw or cooked.