Surface Area of pool 3.142X4, equals 6.284, depth of pool is 1 foot therefore cubic capacity of pool is 6.284X1 equals 6.284.

You will need 6.284 cubic feet of sand, a nice round figure would be 6 1/4 cu. Ft.

You will need 6.284 cubic feet of sand, a nice round figure would be 6 1/4 cu. Ft.