How to Estimate the Cost of Painting for a Water Storage Tank

Measure the radius of the bottom of the water storage tank (radius = the distance from the center of the tank to the outer edge).

Measure the height of the storage tank on one side.

Multiply the number from Step 1 by itself.

Multiply 2 times 3.14 times your result from Step 3.

Multiply 2 times 3.14 times your result from Step 1, times your result from Step 2.

Add your result from Step 4 to your result from Step 5 for the total number of square feet.

Check the label on the gallon of paint for the exact number of surface area coverage in feet.

Divide your result from Step 6 by the number from Step 7 for the total amount of gallons you will need to buy to paint your water storage tank.