How to measure your pond
Get these three numbers right and the liner fits the first time. It takes ten minutes with a measuring tape.
You need three numbers, in feet. Measure the top of the pond, not the bottom.
- 1Length: across the top, from edge to edge, on the longer side.
- 2Width: across the top on the shorter side.
- 3Depth: from the top edge down to the deepest point.
Before you measure
- Use a long measuring tape. Pacing it out with your feet is not accurate enough.
- Finish digging first. Measure the pond as it will be, not as you plan it.
- If the sides are uneven, use the longest length and the widest width.
- Remove stones and roots from the walls. They can puncture the liner.
Sheet size we cut
Sheet length = length + (2 × depth) + 3 ft Sheet width = width + (2 × depth) + 3 ft
The extra 1.5 ft on each edge goes into a trench around the pond to hold the liner in place.
Example: a pond 40 × 30 ft and 6 ft deep needs a sheet of 55 × 45 ft.
Common pond sizes and the sheet you need
| Pond (L × W × depth) | Sheet we cut | Area |
|---|---|---|
| 20 × 15 × 4 ft | 31 × 26 ft | 806 sq ft |
| 30 × 20 × 5 ft | 43 × 33 ft | 1,419 sq ft |
| 40 × 30 × 6 ft | 55 × 45 ft | 2,475 sq ft |
| 50 × 40 × 8 ft | 69 × 59 ft | 4,071 sq ft |
| 60 × 60 × 10 ft | 83 × 83 ft | 6,889 sq ft |
| 100 × 80 × 12 ft | 127 × 107 ft | 13,589 sq ft |