Free tools
Pond calculators
Quick, honest math for the decisions that actually matter, built on the extension-service rules of thumb we use in our reviews. No sign-up, no fluff.
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Pond pump & volume calculator
Enter your pond size and fish load. We estimate the water volume and size the pump, filter and UV to it, using the one-turnover-per-hour rule the extension services publish.
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Pond liner size calculator
Turn your pond dimensions into the flat liner sheet to buy, using the length + twice the depth + overlap rule. Measure the hole, not the yard, and round up.
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Fish stocking calculator
Enter your pond volume and pick a fish. We give a conservative adult stocking limit, because the fastest way to crash a pond is one fish too many.
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