What size pond liner do I need?
Measure the hole, we'll size the liner
Enter your pond's length, width and depth and our EPDM calculator finds the smallest rubber liner that covers it, with spare all round to finish the edge. The table below covers every PE size too.
Three measurements is all it takes
Measure the hole as dug, or mark out the shape with a hose or rope first. Shelves and slopes sit inside these three numbers, so the sheet covers them too.
- LengthThe longest distance across the top of the pond.
- WidthThe widest distance the other way.
- DepthThe deepest point, below any planting shelves.
What size pond liner do I need?
Enter your pond dimensions in metres to find the liner size you need.
Sheet length = pond length + 2 x depth + 2 x edge allowance. Width uses the same sum. Not to scale.
What each liner size builds
Every EPDM and PE sheet with the approximate pond it makes, keeping 30cm spare at every edge (15cm on the smallest sheet). Liner and underlay kits already include their underlay.
| Liner sheet | Pond it builds | Good for | Available in | Underlay to add |
|---|---|---|---|---|
| 1m x 1m | 0.4m x 0.4m, 15cm deep, with 15cm spare at the edge |
Small patio water feature, container pond or spare patch sheet |
Cut from one 3m x 3m sheet |
|
| 1.5m x 5m | 0.5m x 4m, 20cm deep |
Stream, rill or waterfall run |
1 x 3m x 3m
|
|
| 1.5m x 10m | 0.5m x 9m, 20cm deep |
Long stream or rill |
1 x 3m x 5m
|
|
| 2m x 10m | 1m x 9m, 20cm deep |
Wide stream or long formal rill |
1 x 3m x 10m
|
|
| 2.5m x 2.5m | 1m x 1m, 45cm deep |
Small wildlife pond |
1 x 3m x 3m
|
|
| 2.5m x 3m | 1m x 1.5m, 45cm deep |
Small wildlife or patio pond |
1 x 3m x 5m
|
|
| 2.5m x 5m | 1m x 3.5m, 45cm deep |
Long, narrow pond |
1 x 3m x 5m
|
|
| 2.5m x 10m | 1m x 8.5m, 45cm deep |
Canal pond or long stream |
1 x 3m x 10m
|
|
| 3m x 3m | 1.5m x 1.5m, 45cm deep |
Small garden pond with a planting shelf |
1 x 3m x 3m
|
|
| 3m x 4m | 1.5m x 2.5m, 45cm deep |
Small garden pond with a planting shelf |
1 x 3m x 5m
|
|
| 4m x 4m | 2.2m x 2.2m, 60cm deep |
Medium garden pond with shelves |
2 x 3m x 5m
|
|
| 4m x 5m | 2.2m x 3.2m, 60cm deep |
Medium garden pond with shelves |
2 x 3m x 5m
|
|
| 4m x 6m | 2.2m x 4.2m, 60cm deep |
Medium pond or small fish pond |
2 x 3m x 5m
|
|
| 5m x 5m | 3.2m x 3.2m, 60cm deep |
Larger garden pond |
2 x 3m x 5m
|
|
| 5m x 6m | 3.2m x 4.2m, 60cm deep |
Larger pond with marginal shelves |
2 x 3m x 5m
|
|
| 6m x 6m | 4.2m x 4.2m, 60cm deep |
Large garden or fish pond |
4 x 3m x 3m
|
|
| 8m x 8m | 5.6m x 5.6m, 90cm deep |
Large, deep fish pond |
3 x 3m x 10m
|
|
| 8m x 10m | 5.6m x 7.6m, 90cm deep |
Large, deep fish pond |
3 x 3m x 10m
|
|
| 10m x 10m | 7.6m x 7.6m, 90cm deep |
Very large pond or small lake |
4 x 3m x 10m
|
Underlay sized to match
Our 50gsm fabric underlay comes in 3m x 3m, 3m x 5m and 3m x 10m sheets. It is easy to cut and shape around shelves and curves. The table gives the number of sheets for each liner. They are the same sheets our liner and underlay kits contain.
Frequently asked questions
Which liners does the calculator cover?
Our 11 EPDM rubber sizes. For PE liners and the liner and underlay kits, find your pond in the table: each row shows the pond a sheet builds.
How much spare does the calculator allow at the edge?
30cm on every side, which is enough to tuck the liner under stones, slabs or turf. You can change it in the calculator if your edging needs more or less.
My pond is a curved or irregular shape. Which numbers do I use?
Use the longest and widest points across the top and the deepest point. The liner folds neatly into curves and shelves inside those measurements.
Should I choose 1100gsm EPDM rubber or 200gsm PE?
EPDM is 0.9mm synthetic rubber that stretches over awkward shapes and resists sun and ozone at the edges. 200gsm PE is a flexible, lower-cost liner with a black face, also sold in kits with underlay. Our pond planning guide compares them.
Is the sheet exactly the size stated?
Sizes are cut sizes: EPDM sheets can vary by up to 3% and PE sheets by up to 5%. If your pond needs a sheet right at the limit of a size, choose the next size up so you keep the full allowance at the edge.
How do I make a stream or rill?
Choose a long, narrow sheet: 1.5m x 5m, 1.5m x 10m and 2.5m x 10m in PE, or 2m x 10m in EPDM. They line a shallow channel around 20cm deep.