How much is 1 gallon of water in liters?

One gallon of water is equivalent to approximately 3.785 liters. This conversion is based on the standard measurement used in the United States, where the gallon is defined as 128 fluid ounces. When you convert fluid ounces to liters, the resulting figure is about 3.785 liters per gallon. This conversion is important in various fields, including environmental science and plumbing, as it allows professionals to accurately assess and manage liquid volumes. Understanding this conversion helps in estimating the capacity of septic tanks, designing systems, and ensuring compliance with regulations regarding liquid waste management.