How much does water weigh per gallon?

Water weighs approximately 8.34 pounds per gallon at its maximum density, which occurs at around 39.2 degrees Fahrenheit. This weight is a standard that is commonly used in various calculations relating to plumbing, heating, and other maintenance-related tasks. Knowing the weight of water is essential for tasks such as determining load requirements for structures, calculating the weight of water in pipes, or understanding how much weight to expect from water-filled tanks or reservoirs. This weight can vary slightly with temperature and impurities, but for practical purposes in maintenance work, 8.34 pounds is the accepted figure.