Calculating Circles

How to calculate the length around a circle

Formula: Diameter x 3.1416 = Linear Feet Around a Circle

Example: Length Around an 18 foot diameter round Swimming Pool

18 ft x 3.1416 = 56.55 ft (total linear feet around pool)

To add 2 feet of stone (3 inches deep) around this pool: 56.55 feet x 2 feet= 113.10 feet

113.10 feet x 0.25 (3 inch depth) = 28.28 Cubic Feet

28.28 / 27 = 1.05 Cubic Yards

How to calculate the square footage inside a circle

Formula: Length x Width x 0.7854 = Square Feet

Example: Square footage inside a 24 foot diameter round Swimming Pool

24 feet x 24 feet = 576 feet

576 feet x 0.7854 = 452.39 Square Feet (total inside pool)

To add 4 inches of sand evenly across pool:
452.39 feet x .33 (4 inches depth) = 149.29 Cubic Feet

149.29 / 27 = 5.53 Cubic Yards

To be safe, always round up. You would order 6 Cubic Yards of sand.