Calculate liner size for your pond
Liner Size Needed
19.0 × 17.0 ft
Total Area
323 sq ft
Pond Volume
1526 gal
Use Underlayment
Always install geotextile underlayment to protect the liner from roots and rocks.
Install on a Warm Day
EPDM liner is more flexible when warm, making it easier to shape to your pond.
Inputs
Result
Liner length = 10 + (2 x 3) + (2 x 1.5) = 19.0 ft. Liner width = 8 + (2 x 3) + (2 x 1.5) = 17.0 ft. Area = 19 x 17 = 323 sq ft. Volume = 10 x 8 x (3 x 0.85) x 7.48052 = 1,526 gallons.
Inputs
Result
Liner length = 15 + (2 x 4) + (2 x 2) = 27.0 ft. Liner width = 12 + (2 x 4) + (2 x 2) = 24.0 ft. Area = 27 x 24 = 648 sq ft. Volume = 15 x 12 x (4 x 0.85) x 7.48052 = 4,574 gallons.
Liner size = Length + (2 × Depth) + (2 × Overlap) by Width + (2 × Depth) + (2 × Overlap). The overlap is typically 1-2 feet for securing the edges.
Add at least 1 foot of overlap on all sides. For larger ponds or those with rock edges, 1.5-2 feet provides better coverage and easier installation.
Yes, underlayment protects the liner from roots, rocks, and sharp objects. Use geotextile fabric or old carpet padding cut to the same size as your liner.
For fish ponds, use 45 mil EPDM or thicker. Decorative ponds can use 20-30 mil. Koi ponds with larger fish should use 60 mil for extra durability.
Plan your outdoor projects
Last Updated: Feb 12, 2026
This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.