Pool Water & Filling Calculators

Pool water is four questions. How much you have — the gallons number, which sits underneath every chemical dose, every heater BTU, every pump-size calculation. What it costs to put in — the dollar number, which includes a sewer charge most utilities will waive on fill water if you ask. How long the fill takes — the hours number, which is usually longer than most people expect and runs unattended overnight. And in time, how big the standard above-ground pools hold — the lookup number, the quick-glance table for the most common sizes.

Together these four cover everything the water itself does. They don't stray into chemistry territory (that's the chemistry cluster — what to add once it's full), or heat (heating costs are their own cluster), or filtration (pump and filter sizing are their own cluster). They're the water-as-a-physical-thing questions: amount, dollar, time, chart.

The cluster has two honesty stakes — both real, both non-commodity, both surfaced by the calculators' structure rather than by an honest writer hoping you scroll. The first is the sewer-exemption wedgeon the cost page: most US water bills charge sewer per gallon used, but pool fill water never enters the sewer, and many utilities will waive that charge if you ask. On an average pool that's well over a hundred dollars per fill — money a generic “cost to fill” calculator never mentions because it doesn't cost them anything to omit. We show both numbers (water-only and water+sewer) by construction, so the difference is the first thing you see.

The second is the bucket teston the fill-time page: hose flow rate varies enormously by pressure and diameter, and most people don't know theirs. But you can measure it in thirty seconds with a five-gallon bucket — gpm = 300 ÷ seconds — and now the estimate is built on your hose, not a generic average that could be off by half. The bucket-test helper is inline in the rate input; you can fine-tune from there.

3 calculators live now: cost-to-fill (anchored the cluster), fill-time (which brought the hub live), and round-pool gallons — a manufacturer-published capacity chart for the standard Intex/Bestway/Coleman above-ground sizes, the quick-reference lookup most owners actually want (and more accurate than the πr²h formula because it accounts for the real water line — a 52″ pool holds water to ~45″, not 52″). With those three live, the cluster covers the water-as-a-physical-thing side end-to-end.