Pond liner calculator: liner size and volume
The calculator needs JavaScript. The worked example, formula and figures below show exactly how it works, so you can do the sum yourself. A guide, not advice. Check your supplier's or maker's figures before ordering.
Short answer
Worked example
| You enter | Value |
|---|---|
| Longest length of the pond | 3 m |
| Widest width of the pond | 2 m |
| Deepest point | 0.6 m |
| Overlap at each edge | 0.3 m |
| The pond has planting shelves | No |
Liner: 4.8 m × 3.8 m
| Result | Value |
|---|---|
| Liner length | 4.8 m |
| Liner width | 3.8 m |
| Liner area | 18.24 m² |
| Underlay | 18.24 m² |
Show the working
- Liner length: 3 + 2 × 0.6 + 2 × 0.3 = 4.8 m
- Liner width: 2 + 2 × 0.6 + 2 × 0.3 = 3.8 m
- Liner and underlay: 4.8 × 3.8 = 18.24 m²
How it works
- Liner length = L + 2 × depth + 2 × overlap; liner width = W + 2 × depth + 2 × overlap
- Underlay = the same size as the liner
- Volume (L) ≈ L × W × depth × shape factor × 1,000
- Pump flow (L/h) = volume × turnovers per hour
Shelves don't change the liner size (it is sized from the deepest point), but they reduce the volume.
Our default (adjustable)
These are typical planning figures and our own allowances, not facts about your product. Change any of them in the calculator to match your bag, pack or tin.
| Figure | Our default (adjustable) | Kind | Source |
|---|---|---|---|
| Overlap at each edge | 0.3 m | Our assumption Not yet checked against the source | Our choice: change it to suit your job brief v2 L6 (overlap each edge, assumption 0.3 m). Researcher to check against a liner maker's guide. |
| Volume shape factor | Enter from the bag, pack or tin | Our assumption Not yet checked against the source | Our choice: change it to suit your job brief v2 L6: volume ≈ L × W × D × shape factor (assumption, no value given). Researcher to source. |