What is what does a pound of water weigh?

A pound of water weighs exactly one pound or 16 ounces. This is because one pound is defined as the weight of 16 fluid ounces of water at its maximum density, which is at 39.2°F (4°C). However, the weight of a pound of water varies slightly depending on the temperature and pressure, but for most practical purposes, it can be considered to weigh exactly one pound.