How Much Does It Cost to Fill a Pool?

The gallons drive most of the bill. The numbers below assume rectangular pools with a 4.5 foot average depth.

Got a pool with a sloped bottom? Its average depth sits right in the middle between the shallow and deep ends. Curved shapes like rounds and ovals don't need as much water as a rectangle with matching dimensions.

Your bill prices water per 1,000 gallons. For a pool that holds 17,200 gallons, divide the gallons by 1,000, multiply by the rate on your bill, then add any sewer charge. See a sewer line on the bill? Some sewer charges are based on how much water you use, which would add to the cost of filling the pool.

That comes down to your hose and how fast it flows. An easy check: grab a 5-gallon bucket and see how many seconds the hose needs to fill it.

1. 1. Start the hose the way you would for the pool.
2. 2. Fill a 5-gallon bucket under the stream and count the seconds.
3. 3. That timing tells you roughly how many hours you're in for.

A 40-second bucket fill means 7.5 gallons a minute. Fill 15,000 gallons at that rate and you're looking at about 33 hours, so plan on it taking a while.

Suppliers set their own delivery prices, so the number you want from them is a quote for the gallons your pool actually needs. Then compare it to the tap. Figure out what those gallons cost from your water bill, using its rate for every 1,000 gallons along with any sewer fee, and set the two side by side. The gallons table works as a starting guess if your pool's size is still a mystery.

You only need to give it one thing: how many seconds your hose needs to top off a 5-gallon bucket. From there it figures your gallons per minute and tells you the hours for your pool. Your browser stores your pool's gallons for the site, so entering them once is enough.

Expect a pool to lose roughly a quarter inch of water daily to evaporation, and wind or hot weather makes it worse, per Latham Pool. Dropping faster than that? Try a bucket test. Set a water-filled bucket next to the pool, then watch how far each one falls across a full day. A gap of more than 1/8 inch between the two levels points to a possible leak.

• Gallons: surface area in square feet, multiplied by average depth in feet, multiplied by 7.48 (round and oval pools use 5.9 instead).
• Average depth on a sloped bottom: shallow depth plus deep depth, then split in half.
• Fill cost: take the gallons, split them into 1,000-gallon units, multiply by your bill's rate for each unit, then add any sewer fee.
• Hose speed: 5 gallons divided by your bucket seconds, times 60, gives your flow in gallons a minute.
• Fill time: gallons divided by gallons a minute, then divided by 60, and that's your hours.
• Units: 1 US gallon equals 3.785 liters, and 1 cubic meter equals 1,000 liters.