Every number for a thriving pond
Size your pond, liner, pump, filtration, and koi stocking in seconds, then back it up with straight-talking build and care guides plus gear picks. Koi ponds and water gardens.
Length
14 ft
Width
10 ft
Avg depth
2.5 ft
2,600 gallons
9,840 L · liner 21 × 17 ft
Most-used calculators
Tap a tool, enter your numbers, get an answer plus the gear that fits.
Pond Volume
Gallons & liters from your dimensions.
Koi Stocking
How many koi can your pond hold?
Pump Size (GPH)
Right pump flow for healthy turnover.
Pond Liner Size
Liner + underlayment with overlap.
Waterfall Pump
GPH for your spillway and head.
UV Clarifier Size
Beat green water with the right UV.
Explore the whole hub
Calculators
11 free tools to size your pond and gear.
Explore → 🐠Pond Fish & Koi
Care, size, and stocking by species.
Explore → ⭐Gear Reviews
Pumps, filters, UV, liners, aerators, and more.
Explore → 💧Water & Care
Cycling, algae, parameters, and seasons.
Explore → 📊Reference Charts
Quick-look tables you can bookmark.
Explore → 🛟Troubleshooting
Fix green water, string algae, sick koi.
Explore →Sized to real equipment
Our calculators do not just give a number, they translate it into the pump GPH, UV wattage, liner size, and gear that actually fits your pond.
Koi ponds and water gardens
From a first small water garden to a serious koi pond, the tools and guides cover building, stocking, and year-round care.
No fluff, no fear-mongering
Clear, practical advice grounded in how pond keeping actually works, so you can make confident decisions fast.
Pond Build & Maintenance Planner
Build planner, stocking planner, water-test log, and seasonal maintenance schedule, in one printable PDF that keeps your pond healthy year-round.
Get the Planner for $39Are you a pond or koi brand?
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