How much does a gallon of water weigh?

Answer: A gallon of water in everyday life weighs approximately 8.34 pounds or 3.78 kilograms.

A US gallon of water weighs approximately 8.34 pounds or 3.78 kilograms at standard temperature and pressure (62°F or 17°C) and is most widely used. However, the weight of the water can vary slightly depending on a few factors like types of gallons, temperature, pressure, and impurities. In this article, we will learn about how these factors affect the weight of water.

There are two main types of gallons:

• US gallon: This is the most common measuring unit. It contains 231 cubic inches (3.785 liters). A US gallon of water weighs about 8.34 pounds or 3.78 kilograms. It is used at room temperature (17°C or 62°F ).
• Imperial gallon: It is used in UK. It is slightly larger than the US gallon and contains 277.42 cubic inches (4.546 liters). An imperial gallon of water weighs 10.02 pounds or 4.546 kilograms. It is used at the densest temperature (4 °C or 39 °F).

Below are various factors affecting the density and weight of water:

• Temperature: Colder water is denser than warmer water, so it will weigh slightly more per gallon than usual. Water is densest at around 39°F (4°C).
• Pressure: Water is less dense at higher altitudes due to lower air pressure, so it will weigh slightly less.
• Impurities: If the water contains dissolved minerals or other substances, it will weigh slightly more because of the mass of impurities. That’s why impure water wighs more than pure water.

Conclusion

Therefore, 8.34 pounds is an approximate value for the weight of a gallon of water. But, it should be remember that the weight of water is affected by many factors like temperature, pressure, impurities, etc.