Why Does Meat Shrink When Cooked? (And How to Calculate It)

You bought a pound of beautiful ground beef, formed it into thick, juicy patties, and threw them on the hot grill. Ten minutes later, you pull them off only to realize they have shrunk drastically, barely covering half the hamburger bun.

What happened to all that meat?

The Science of Meat Shrinkage

Raw meat is composed of three main things:

Water (about 75%)
Protein (about 20%)
Fat and Carbohydrates (about 5%)

When you expose raw meat to heat, two critical things happen simultaneously.

First, the muscle fibers (proteins) begin to denature and coagulate. As they tighten and contract, they act like a sponge being squeezed, wringing out the water trapped inside. This water evaporates in the pan or drips down into the grill grates.

Second, the solid fats in the meat begin to melt (render) and turn into liquid oil, which also drains away from the meat.

How Much Will Your Meat Shrink?

The amount of shrinkage depends on the fat content, the cooking method, and the target temperature.

Ground Beef (80/20): Expect about 25% shrinkage. A 4 oz raw patty will yield a 3 oz cooked burger.
Chicken Breast: Expect about 20% shrinkage. Since chicken is very lean, less fat renders out, but it still loses significant water weight.
Steak: Shrinkage varies by doneness. A rare steak will shrink less (around 15-20%) because less moisture has been cooked out compared to a well-done steak (up to 30%).
Bacon: Bacon is mostly fat. It can shrink by an astounding 60% as the fat renders out in the pan!

Planning Your Grocery List

If you are meal prepping for the week and need exactly 16 ounces of cooked chicken breast, buying 16 ounces of raw chicken will leave you short. You must account for the shrinkage.

Use our Meat Shrinkage Calculator to work backwards. Simply input your desired cooked yield, and the calculator will tell you exactly how much raw meat you need to buy at the grocery store.

Need exact calculations for your next kitchen project? Check out our free Meat Shrinkage Calculator to make the math effortless!