Free water operator tool
Circular tank area calculator
Find the surface area of a circular tank or clarifier in square feet from its diameter. The tool uses 0.785 times the diameter squared and shows every step. Surface area is the first move in many storage and clarifier problems on the Class D exam.
How the tool works
The area of a circle is 0.785 times the diameter times the diameter. The 0.785 comes from pi divided by four, the standard operator shortcut for working from a diameter instead of a radius. Open the worked solution to see the diameter you entered squared and multiplied through.