Whether you’re filling your pool up by hose or water truck, you probably want to know how long does it take to fill a pool, right? After all, the thought of water overflowing and turning your backyard into a swamp isn’t comforting. Before we get started, we’ll warn you, there is math involved to calculate how long filling your pool will take.
The amount of time that your pool takes to fill with water is based on two factors. The first factor is the method of filling. The two most common ways are by water truck or your home’s hose. The second factor is how many gallons are in your pool. Once you understand these, you can have a very accurate estimate for how long you’ll be waiting to enjoy your slice of paradise.
Full Process Start To Finish
- Gather the dimensions (average depth, length, width) of your pool
- Calculate how many gallons are in your pool (from cubic feet)
- Determine water source – hose or water truck
- Understand your hose flow rate or amount of gallons per truckload
- Measure how long the hose or truck will take to fill your pool

First Answer: How Many Gallons Is My Pool?
To determine how long your pool takes to fill you must first figure out how many gallons of water are in your pool. If you have a rectangular pool this will be easy. For folks with a plunge pool, your pool will be a minimal gallonage and therefore, we be quicker to fill up. If your pool is empty when you are measuring it, keep in mind the pool will be full when the water is halfway up the waterline tile.
Take three depth measurements, one at the shallow end, one halfway down the length and one at the deep end. Add all three measurements up and divide by three. This is your average depth. Measure the length and the width of the pool then multiply them together with the average depth, and you will have the cubic feet of the pool. Multiply cubic feet by 7.48 and you’ll have the gallons.
Pro Tip For Free Formed Pools
If you have a free formed pool with no recognizable shape you can still get a rough volume by taking multiple width measurements and length measurements and finding the average length and width to use in the above calculation. This will not be accurate, but will be able to give you an estimate of the total gallons.
An Example For Finding Out How Long Does It Take To Fill A Pool
Let’s assume you have a 15 x 30 rectangular pool. Additionally, you have an average depth of 4 feet. So, 15 x 30 x 4 = 1800 cubic feet. 1800 x 7.48 = 13,464 gallons. A garden hose typically flows at a rate of 10 gallons per minute. If you don’t know the hose flow rate, there is a way to figure it out. You can take a 5 gallon bucket and time how long it takes for your hose to fill the bucket. If your hose fills the bucket in 28 seconds, you multiply 5 x 60 = 300, then divide 300 / 28 = 10.7 gallons per minute.
Then, to figure out how long it will take to fill the pool, you divide the total gallons by the flow rate. So, in this case we divide 13,464 gallons / 10.7 gallons/minute to get 1,258 minutes. Divide that by 60 and we get 20 hours and 58 minutes. So in this case it’ll take approximately 13 hours to fill the pool with a garden hose.
Consider Trucking In Water For Efficiency
Another common way to fill a pool is with trucked in water. In this case you still need to know your total gallons. Then, you’ll also need to know the volume each truckload of water will be. If each truckload is 4500 gallons, the above example would require 13,464/4,500 = 3 loads of water. Trucking in your water is the fastest way to fill your pool and in many cases the only way that makes sense. If you are on a well for example, you typically do not want to fill the pool with your hose. It makes sense to have the water delivered for the health of your well.
Bottom Line On Asking How Long Does It Take To Fill A Pool
There you have it, the amount of time a pool takes to fill up with water is based on two factors. Those two pieces of critical information are the pool’s size (in gallons) and your water source. Using a hose or water truck are drastically different for setting a timeline. Assuming you know the answer to those factors, you can predict when you’ll be yelling “cannonball” and taking your first refreshing dip.
One last thing to note, the water chemistry of your pool will not be balanced when the water is done filling up. Most folks don’t care much about that aspect on the first day. It will take a bit longer for your pool builder to properly start up your pool.
Leave a Reply