Converting pounds to gallons requires the material’s density. Pounds measure weight; gallons measure volume. The same weight of water, honey, flour, or fuel occupies a different amount of space.
Pounds to gallons formula
For density in pounds per US gallon, use:
Volume (US gallons) = Weight (pounds) ÷ Density (pounds per US gallon)
For example, water weighs about 8.34 pounds per US gallon under common reference conditions. Ten pounds divided by 8.34 is about 1.20 US gallons.
Use the right density
Choose a density that matches the substance and conditions. Liquid density can vary with temperature and composition. Powders such as flour also vary with packing and moisture, so a result based on a typical density is an estimate.
The US liquid gallon differs from an Imperial gallon. Confirm which gallon system your density value uses before calculating.
Use the pounds to gallons calculator to select a material or enter a custom density and see the result in gallons, liters, cubic inches, or cubic feet.