Pond liner calculator: what size pond liner do I need?
18 ft × 14 ft
252 sq ft of liner · pond 10 × 6 ft and 2 ft deep, 2 ft of overlap at each edge · for a 10 × 6 ft pond 2 ft deep with 2 ft of overlap
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3/8 or 10' 6".
18 ft × 14 ft
252 sq ft of liner · pond 10 × 6 ft and 2 ft deep, 2 ft of overlap at each edge
A pond 10 ft long, 6 ft wide and 2 ft deep needs an 18 ft × 14 ft liner, 252 square feet, with 2 ft of overlap at every edge: each side is the pond plus twice the depth plus twice the overlap.
A worked example
A kidney-shaped pond 11 ft 4 in long, 7 ft 9 in wide and 2 ft 6 in deep, with 18 in of overlap, needs a 19 ft 4 in × 15 ft 9 in liner. Twice the depth is 5 ft and twice the overlap 3 ft, so 8 ft goes on each side: 11 ft 4 in + 8 ft and 7 ft 9 in + 8 ft, 304.5 square feet. A free-form pond is measured as the rectangle that holds it.
How do I work out the size of a pond liner?
Add twice the deepest depth and twice the edge overlap to the pond length, then do the same with the width. An 8 by 5 ft pond 18 in deep with 1 ft of overlap is 8 + 3 + 2 = 13 ft by 5 + 3 + 2 = 10 ft, a 13 × 10 ft liner. The calculator does the sum in feet and inches.
What size liner for a round pond?
Use the diameter as both the length and the width, because the liner comes square. A round pond 7 ft across and 2 ft deep with 1 ft of overlap takes a 13 × 13 ft liner. The corners that hang past the round edge are folded under or cut off when the pond is finished.
What else it is called
A pond liner is also called a pond membrane and is sold in EPDM rubber or PVC, in sizes by length and width in feet. The underlayment that goes beneath it is cut to the same size. For the gravel or river rock around the edge, the river rock calculator gives the cubic yards.
Liner sizes
| Pond | 1.5 ft deep | 2 ft deep | 3 ft deep |
|---|---|---|---|
| 6 × 4 ft | 13 ft × 11 ft | 14 ft × 12 ft | 16 ft × 14 ft |
| 8 × 6 ft | 15 ft × 13 ft | 16 ft × 14 ft | 18 ft × 16 ft |
| 10 × 6 ft | 17 ft × 13 ft | 18 ft × 14 ft | 20 ft × 16 ft |
| 10 × 8 ft | 17 ft × 15 ft | 18 ft × 16 ft | 20 ft × 18 ft |
| 12 × 8 ft | 19 ft × 15 ft | 20 ft × 16 ft | 22 ft × 18 ft |
| 15 × 10 ft | 22 ft × 17 ft | 23 ft × 18 ft | 25 ft × 20 ft |
| 20 × 12 ft | 27 ft × 19 ft | 28 ft × 20 ft | 30 ft × 22 ft |
Liner length × width with 2 ft of overlap at every edge. With 1 ft of overlap, take 2 ft off each side.
Where the numbers come from
- Liner size is geometry: the liner runs down one wall, across the bottom and up the other, so each side is the pond length (or width) plus 2 × the deepest depth, plus the overlap you leave at each edge, twice. Square feet are length × width.
- Shelves and sloped sides do not change it: the liner still climbs the full depth on each side and crosses the full length, so the same count covers them. Sizes are given to the nearest 1/16 in.
Measure the hole after digging, at its longest, widest and deepest points; a free-form pond is measured as the smallest rectangle around it. Order the next liner size up from the one you get, and cut the rest off once the pond is filled and the liner has settled into place.
By Javier Miralles · Last updated . How this site is made.
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