How much does a gallon of water weigh?

How much does a gallon of water weigh?

• A. 7.5 lb
• B. 8.33 lb
• C. 9.0 lb
• D. 10 lb

Answer: (B)

Weight of water comes from its density times volume. A US gallon is 3.785 liters, and water’s density is about 1 kilogram per liter at typical temperatures. Multiply 3.785 liters by 1 kg/L to get roughly 3.785 kilograms, then convert to pounds (1 kg ≈ 2.2046 lb) to get about 8.34 pounds. So the practical answer is around 8.33 pounds per gallon. The other numbers would imply densities far from that of water, which isn’t correct for a gallon of water.

Weight of water comes from its density times volume. A US gallon is 3.785 liters, and water’s density is about 1 kilogram per liter at typical temperatures. Multiply 3.785 liters by 1 kg/L to get roughly 3.785 kilograms, then convert to pounds (1 kg ≈ 2.2046 lb) to get about 8.34 pounds. So the practical answer is around 8.33 pounds per gallon. The other numbers would imply densities far from that of water, which isn’t correct for a gallon of water.