As a unit of volume, the fluid ounce is equal to 1/16of a pint, or 29.57 millilitres, in the U.S. Customary System and to 1/20of a pint, or 28.41 millilitres, in the British Imperial System. As a unit of weight, the ounce derives from the Roman uncia (meaning “twelfth part”), which was 1/12 of a Roman foot or ounce.

The fluid ounce is a measure of volume rather than weight. There is 16 fluid oz. to a pint in the U.S. customary system, and 20 fluid oz. to a pint in the Imperial system used elsewhere in the world. An Imperial fluid ounce weighs exactly 1 oz., so conversion between volume and weight is not necessary.

Ice cubes float on water, so no, they don’t weigh more than water. Ice retains the same weight as water, but water expands when frozen, making it become less dense, thus making it float on water. Water expands when it freezes so its density is less than that of liquid water.

The real answer for ‘when to weigh it’ is that you measure it as packaged. So, frozen vegetables get measured while still frozen. The manufacturer cannot control what method you might use to cook the vegetables, so they could soak up water and weigh more, or weigh less if you roast them.

When it comes to frozen shrimp, skip weighing them. This number (which is clearly marked on the packaging) represents raw, unfrozen weight, so if your recipe calls for 8 ounces of large shrimp, simply count out 15 shrimp—half of the top of the range. That way you’ll be sure to have enough post-thaw.

Frozen Cooked Medium Peeled and Deveined Tail-On Shrimp, 12 oz: 41-60 shrimp per pound.

Nope. A given amount of water, when frozen, will weigh exactly the same as it did when it was liquid. An equal volume of water, when frozen, will actually weigh less than an equivalent volume of a liquid, since water actually becomes less dense when it becomes a solid.

Frozen meat weighs more than unfrozen meat only to the extent that during the freezing process water has condensed and frozen on its surface. The meat itself and the water it contains weigh the same.

If you buy frozen berries, you weigh them frozen. In the case of the berries, it won’t make a huge difference. In the case of the chicken, it can be more impactful.

Water is the only known non-metallic substance that expands when it freezes; its density decreases and it expands approximately 9% by volume.