EPDM Pond Liner Size Calculator
Calculate EPDM pond liner length, width and area from pond dimensions and anchor overhang, so you order the right panel size.
How This Calculation Works
Liner length equals pond length plus twice the depth plus twice the overhang, and liner width follows the same pattern. For a 20 by 12 foot pond 3 feet deep with 2 feet of overhang, the liner is 30 by 22 feet. Liner area is the product of those two dimensions.
Field Calibration & Rate Reference Chart
| Surface ac | Avg depth | Acre-feet | Copper lb @ 1 ppm |
|---|---|---|---|
| 0.25 | 4 ft | 1.0 | 2.7 |
| 0.5 | 4 ft | 2.0 | 5.4 |
| 0.5 | 6 ft | 3.0 | 8.2 |
| 1.0 | 4 ft | 4.0 | 10.9 |
| 1.0 | 6 ft | 6.0 | 16.3 |
| 1.5 | 5 ft | 7.5 | 20.4 |
| 2.0 | 5 ft | 10.0 | 27.2 |
| 2.0 | 8 ft | 16.0 | 43.5 |
| 3.0 | 6 ft | 18.0 | 49.0 |
| 5.0 | 6 ft | 30.0 | 81.6 |
Common Questions
How do I calculate EPDM liner size?
Add twice the depth and twice the overhang to both the length and the width of the pond. A 20 by 12 foot pond 3 feet deep with 2 feet of overhang needs a 30 by 22 foot liner. The overhang anchors the liner in a trench.
How much overhang do I need for a pond liner?
Allow at least 1 to 2 feet of overhang on each side to anchor the liner in a trench and accommodate settling. Steep or unstable banks need more. The overhang is added to both dimensions.
Should I use a single liner panel or seams?
A single panel is stronger and less likely to leak, so order the largest panel your site allows. Seams are a common failure point. If a seam is unavoidable, use the manufacturer's splice kit and follow the cure time.
Do I need an underlayment beneath EPDM?
Yes, a geotextile underlayment protects the liner from punctures by rocks and roots. It also cushions the liner against soil movement. Skipping it is a leading cause of liner failure.