What is the Formula for water in a cylinder?

This is kind of tricky, but here are the basics: Volume is the surface area of the cylinder multiplied by the depth of the water. Do not mix feet and inches, convert all dimensions to feet or inches, depending on the application. To calculate the surface area, measure the inside diameter of the cylinder, divide the diameter by 2 and then multiply by Pi (3.1416). Multiply the surface area by the depth of the water and use following information for conversion: water is 231 cubic inches per gallon or 7.481 gallons per cubic foot.