🐟 Backyard Pond Cost Calculator

Estimate the total cost to build a backyard pond or koi pond. Covers liner, pump, filter, plumbing, and accessories.

Project Details

Pond Length (feet)

Pond Width (feet)

Pond Depth (feet)

Min 2 ft for goldfish, 3+ ft for koi

Fish? (0=no, 1=goldfish, 2=koi)

Waterfall? (0=no, 1=yes)

Your Estimate

Enter your details and hit Calculate to see results.

More Tools You Might Need

Pond Liner (EPDM)

The waterproof membrane — the foundation of the pond

Pond Underlayment

Protects the liner from rocks and roots

Circulates water and powers the filter

Keeps water clean for fish — biological filtration

Kills algae and keeps water crystal clear

Catches leaves and debris before they sink

Flexible Tubing

Connect pump to filter and waterfall

Monitor water quality for fish health

Keep predators out and leaves from falling in

Waterfall Spillway

Creates a natural-looking waterfall edge

Pro Tips

✓ Liner size = (length + 2×depth + 2) × (width + 2×depth + 2) for overlap
✓ Budget for a pump that circulates the full volume every 1-2 hours
✓ Koi ponds need at least 3 ft depth and a stronger filtration system
✓ Add beneficial bacteria monthly to keep the ecosystem balanced
✓ A waterfall adds aeration — good for fish and reduces algae

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