How much does one gallon of water weigh approximately?

One gallon of water weighs approximately 8.33 pounds. This value is derived from the standard weight of water at its maximum density, which occurs at around 39.2 degrees Fahrenheit. At this temperature, one US gallon (equivalent to 128 fluid ounces) is often used as a benchmark in various scientific and practical applications. Understanding this weight is particularly important in calculations involving fluid weight, such as those encountered in plumbing, construction, and various engineering fields. Thus, the approximate weight of one gallon of water being 8.33 pounds is a fundamental fact used in many contexts, emphasizing its significance.