Is a 20×40 Pool Too Big?

is a 20x40 pool big enough?

Bigger is better they say! But is a 20×40 pool too big? That’s a great question and one that we will dive into in this article. It really is subjective but you might be surprised at overall what people think in general about big pools. Let’s answer the question directly though.

A 20’x40′ pool is 800 sq. ft. and holds approx. 30,000-40,0000 gallons of water depending on your pool depth. A pool of this size easily fits 6-8 people for swimming, games, relaxation, and lounging. These pools are the perfect size for diving pools that reach 8ft deep to accommodate safe head-first diving. This pool isn’t too big if you have an average to large size family and host medium-sized gatherings many times throughout the swim season.

I’m going to detail some more information about 20×40 pools that in my opinion makes them ideal if you can afford them and have the time to maintain them.

An Inground Diving Pool 18’x43′

What are the Pros and Cons of a 20’x40′ Swimming Pool?

There are a few other pool sizes that I have written specific blogs about like the, 15×30 pool and if it’s big enough, but I feel that this size pool is the first one that really requires its own list of advantages and disadvantages to having such a big pool. There is a big divide among pool owners of various sizes about these bigger pools, but I rarely hear complaints about those who did go big. Let’s dig into some of that though below:

Advantages to having a 20’x40′ Pool

  • Depth Choices: This size pool is long enough to allow 8 ft depths for diving without too steep of a slope.
  • Ease of Mind: With the depth comes the relaxation of not having to yell at kids for diving head-first into the pool
  • Large Deck: Naturally with a pool this size, you’ll have a massive deck to go along with it. People underestimate how much the deck is utilized in family and friend gatherings at the pool.
  • Size of Shallow End: Another thing people don’t think about is how much time is spent in the “shallow end”, meaning 4ft deep. This size pool allows a huge shallow end with a very deep end!

Disadvantages to the 20’x40′ Pool

  • Cost: Literally, just about everything about this size pool is more costly installation, chemicals, equipment, utility bills and the list goes on and on.
  • Heating: This pool is just too big to heat often. It’s will cost an arm and a leg each time you do.
  • Cleaning: If you don’t have a weekly cleaner, then be prepared to spend some serious time keeping up with this pool. It is some work! I also suggest investing in a serious pool automatic cleaner like this Dolphin. It is legit!
  • Pool Water Chemical Balance: Be prepared to learn a whole lot about pool water and how to keep it balanced. There are kits out there but you can also look at the Sutro Pool monitoring device. It’s got an app for your smartphone but if it’s too pricey, the good old Taylor chemical pool test kit is tried and true.

How Many People Can Fit in a 20’x40′ Pool?

At the beginning of the article, I said that this pool will hold 6-8 people. That is a super conservative estimate. This pool can fit 12 adults in the pool playing games and having fun easily. You won’t be swimming laps while people are goofing around and having fun but everyone will easily fit in the pool. In the picture below, you can see 8 kids playing in only half of the pool which is only 16’x40′.

4th of July Party in a 16’x40′ pool

How Deep Should My 20’x40′ Pool Be?

This is a great question and it really depends on who is going to be using your pool and what they will be doing in it. I go into great detail about pool size and depth in my article here.

My recommendation for this size pool, I would go at least 8 feet deep and build a beautiful set of jumping rocks with a slide on the end of the pool. I don’t like the look of a diving board so I would opt for more natural jumping rocks for kids to jump from.

If 8 feet is too deep, then I would wonder if scaling the size back to a 16’x32′ swimming pool with 6.5 feet would be a better option. Maybe even a sports bottom in the middle of the pool for jumping which would still leave most of the pool open for volleyball and basketball games.

Volleyball in a 16’x36′ Pool

I believe if you aren’t interested in the depth that you can achieve with the 20’x40′ then it might not be worth the extra cost to build so big. Although, there are a ton of other reasons and this is just my personal opinion. You can still even go 6.5 feet deep on a 20’x40′ and include the slide as mentioned before.


My closing thoughts are that a 20×40 isn’t too big! I think it’s a massive pool but perfect for a big family and a home that hosts many people over the summer and throughout the year if you live somewhere warm year-round. Clearly, though, money shouldn’t be an issue for you if you go for a pool this size, the initial cost and the upkeep is not cheap, and is an ongoing investment.


The founder of I wanted a place to share all of the great information from my family to other pool lovers, builders, and those looking to buy a pool.

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