Free water operator tool
Water tank volume calculator
Find the volume of a rectangular or round tank in gallons. Enter the dimensions and the tool works out the cubic feet, then converts to gallons at 7.48 gallons per cubic foot, showing every step. The math is the same anywhere, and it is on the Texas Class D water exam.
How the tool works
A rectangular tank holds length times width times water depth, in cubic feet. A round tank holds its circle area (0.785 times diameter squared) times water depth. One cubic foot of water is 7.48 gallons, an exact-enough operator constant, so multiplying cubic feet by 7.48 gives gallons. Nothing here is a hidden number: open the worked solution to see each value traced to a dimension you entered or the conversion above.