What is the weight of a gallon of water?

Answer by  HenryCrun (63)

A US gallon of water weighs about 8lb, but it depends on the temperature. At around 40degF it weighs a little more, because water is densest at this temperature.

Answer by  monkeyz (3150)

First, it depends on whether you are using a US or a UK gallon. The temperature also matters, as the weight of water will change based on its temperature. A US gallon at roughly 40 degrees F is 8.34 pounds. A UK gallon at 62 degrees F is 10 pounds.

Answer by  esteban (1334)

This actually depends on the temperature of the water. At 4 degrees Celsius, water weighs 8.343 pounds per gallon, at 40 degrees Celsius, it weighs 8.279 pounds per gallon, and at 80 degrees Celsius, water weighs 8.109 pounds per gallon.