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Pond liner size and roll length calculator

Calculate liner length and width from preliminary dimensions or rope measurements of the excavated basin. Edge allowance, order rounding and roll fit can also be checked.

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01

Your inputs

The starting values are an example.

For rope measurement, this is already included in the rope, so it is not added separately.
Specify the size required for fixing.
Both sides are rounded up to this increment.
We show whether it fits in one piece and what length is required.

Decimals: 12.5 · Thousands: 1,234.56. Follow the field instructions for lists.

02

Your result

Enter your values and select Calculate.

Your calculation will appear here.

Your result will include the relevant values and units.

Understand the calculation

Formula and example

How it is calculated

liner length ≈ pond length + 2 × depth + 2 × edge; for rope measurement: rope length + 2 × edge

Worked example

4 × 3 m top dimensions, 1 m depth and 0.5 m edge per side: 7 × 6 m liner.

Things to check

  • For irregular basins, measure with a rope following the entire surface after excavation, running over steps and depressions. The rope mode already includes these, so depth is not added separately.
  • Both sides of the custom-sized rectangle are rounded. For fixed-width rolls, the original required width must fit, and only the purchased length is rounded.
  • Specify the edge allowance with your own size required for fixing. Fit into one piece is a geometric check; fitting, underlay, waterfalls and pipe penetrations require separate planning.

Frequently asked questions

How do I measure with a rope?

Run the rope along the entire surface in the two main directions of the excavated basin, following every step and depression. The fixing edge is added separately in the calculator.

Why isn't the pond water surface area enough?

The liner covers the sides and the bottom of the basin, and must be fixed at the edges. Therefore, the simple product of top length and width does not give the required material size.