Any easy way to determine your pool’s surface area is to multiply the length by width by depth by 7.5. This way you’ll calculate the volume in gallons. Length multiplied by width provides the pool’s surface area. By further multiplying that by the depth you’ll calculate the volume in cubic feet.
Alternatively, first measure the length and width of your pool area. Using a simple formula, you can calculate the area. For example, if you have a rectangular pool, multiply length by width by 1.6 to get a square feet surface area. Divide this total by the coverage square footage of paint you desire to use. This way you’ll know the square footage of the area to be painted and you’ll know how many gallons of paint you’ll need.
Note: always check if the pool paint needs a single or multiple coat and a primer.