Enter your pool volume, water rate, and hose flow — get the cost of a full or partial fill, and how long the hose will run.
The fill cost formula
cost = gallons × (rate per 1,000 gal ÷ 1,000)
fill hours = gallons ÷ (hose GPM × 60)
The rate on your bill is the whole game, and it varies more than people expect — $3/1,000 gal in water-rich regions to $12+ in the arid Southwest, usually split between "water" and "sewer" line items. Since pool water never enters the sewer, many utilities will credit that portion for a documented pool fill.
A worked example
Filling 15,000 gallons at $6 per 1,000: $90, running a 10 GPM hose for 25 hours. A one-third drain-and-refill to knock 90 ppm off high CYA: 5,000 gallons, $30, and about 8 hours of hose time — cheap compared to fighting bad chemistry all season.
Well water and trucked water
Filling from a well is "free" but can pull iron and metals that stain plaster the moment chlorine hits them — sequestrant first if your well runs rusty, and pace the fill to protect the well pump. Trucked water costs several times city rates but arrives in hours, pre-balanced in some markets. For most city-water pools, the hose wins on price every time.
Frequently asked questions
How much does it cost to fill a pool with water?
City water typically runs $4–10 per 1,000 gallons including sewer charges, so a 15,000-gallon pool costs roughly $60–150 to fill from the tap. Some utilities waive the sewer portion for pool fills if you ask — worth a call, since sewer is often half the bill.
How long does it take to fill a pool with a garden hose?
A standard hose delivers 8–12 gallons per minute. At 10 GPM, 15,000 gallons takes 25 hours — plan on a full day and night, and don't leave it completely unattended near the top.
Is water delivery cheaper than the hose?
Almost never cheaper — trucked water typically costs several times tap rates — but it fills a pool in hours instead of days and doesn't stress a well. It's the right call for well water with iron, or when the pool must open this weekend.
Do I have to drain my pool to fix high CYA or salt?
Partial drains are the standard fix — and this calculator prices them. To cut a level by half, drain and refill half the volume; the water math is linear.