Use the following formula to calculate the liner size needed for your pond. To prevent liner from falling into the pond, a 1 foot overlap is suggested.

Length + (Depth x 2) + (Overlap x 2)
Width + (Depth x 2) + (Overlap x 2)

Example: Pond measures 12’ long x 17’ wide x 3’ deep.

12 + (3x2) + (1x2) = 20
17 + (3x2) + (1x2) = 25

A 20’x25’ liner is recommended for this pond.