What Is the Weight of 1 Gallon of Water?

Edwin Remsberg/age fotostock/Getty Images

The weight of 1 gallon of pure water at room temperature is 8.329 pounds. The weight varies with temperature, ranging from 8.344 pounds at 32 F, the freezing point, to 7.996 pounds at 212 F, the boiling point. Water is at its heaviest at 39.2 F.