Pond Liner Calculator
This pond liner calculator shows how big the liner for your garden pond must be: enter the maximum length, width and depth, choose the edge overlap and read the liner size and the pond volume.
Example: Pond length (maximum) 13 m / ft · Pond width (maximum) 10 m / ft · Depth 3.3 m / ft · Edge overlap per side 1 m / ft · Unit: Feet · Shape for the volume: Free form (basin, shallow edges) · Shape factor 0.7 → Liner needed: Liner 21.6 × 18.6 ft, pond volume about 8,504 liters. Source: Wikipedia – Pond liner (Teichfolie: Verwendung, Materialien). Updated: .
How it is calculated
A pond of 13 × 10 ft and 3.3 ft deep needs a liner of about 21.6 × 18.6 ft with a 1 ft edge overlap. The calculator works out the liner size from the largest pond dimensions, the depth and the overlap.
How it is calculated
The liner has to follow the profile of the pond: it runs down one side, across the bottom and up the other side. So you add the depth twice in each direction: length plus two times depth plus two times edge overlap. The same applies to the width. The pond volume is estimated from the box and a shape factor you can adjust, because real ponds have shallow edges and a basin.
What to watch for
- Measure the dug hole, not the plan: small deviations add up on a liner.
- A larger edge overlap makes it easier to cover with stones, gravel or turf.
- An underlay belongs beneath the liner to protect it from sharp stones and roots.
More tools for garden and water: the aquarium volume calculator, the gravel calculator and the volume converter.
Frequently asked questions
How big must a pond liner be?
Pond length plus twice the depth plus twice the edge overlap, and the same for the width. For 13 × 10 ft, 3.3 ft deep and 1 ft overlap that is about 21.6 × 18.6 ft.
How much edge overlap makes sense?
Usually 8 to 20 in (20 to 50 cm) per side, so the liner disappears under stones or the edging. The calculator lets you choose any value.
How do I calculate pond volume?
Length times width times depth gives the box. Because ponds have shallow edges and a basin, it is multiplied by a shape factor of usually 0.5 to 0.8.
Do I need to add steps and planting shelves?
Yes, every step lengthens the path of the liner. The calculator assumes a simple basin; plan extra liner for steps.
Sources and legal basis
As of: · Editorial policy
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