How much does one gallon of water weigh?

One gallon of water weighs approximately 8.34 pounds at its maximum density, which occurs at around 39.2 degrees Fahrenheit (4 degrees Celsius). This value is widely accepted and commonly used in calculations related to water treatment, environmental studies, and various scientific applications. The weight of water can vary slightly with temperature, but 8.34 pounds remains a standard reference for most practical purposes. Understanding this figure is crucial for drilling, as it helps in calculating fluid weight in boreholes, assessing pressure, and determining the need for additives or adjustments in drilling fluid to maintain optimal performance.