Sizing Your Above Ground Pool Pump

Sizing your above ground pool pump is crucial to the overall performance of your swimming pool. An undersized pump lacks the power needed to circulate your water properly to prevent algal blooms. Adversely, a pump that is too large will completely bypass your filter altogether. This, too, creates a dirty pool. In a way, it’s similar to the likes of Goldilocks and The Three Bears. You don’t want a pump that is too big or too small, you want one that is JUST right.

How can you determine which size pump is right? Let’s explore.

What Size Pump Do I Need?

The General Sizing Rule

For the most part, above ground pools are similar in size and shape. Therefore, unlike most inground pools, there aren’t too many extra variables you need to consider when sizing your pool pump. The one thing you need to pay attention to, though, is the maximum gallons per minute (GPM) your pool filter can handle. Your pump’s GPM should never exceed your filter’s GPM. We will show you how to check that later in the blog.

To be honest, sizing the pump is actually pretty straightforward. There is a general rule we use that makes it very easy to pick.

For round above ground pools up to 24 ft. ( pools with less than 15,300 gallons) use a 1 HP pump.

For round above ground pools over 24 ft.  (pools with more than 15.300 gallons) use a 1.5 HP pump.

Don’t Know How Many Gallons Are In Your Pool? 

If you are unsure how many gallons your above ground pool has, review the charts below.

Is My Filter Too Small For My New Pump?

After selecting your pool pump, verify the GPMs of your pool filter. The GPM information is typically listed on the outside label on the filter housing. If unavailable or weathered, you can also locate this information in the user manual. If for whatever reason you cannot find your manual, we recommend doing a quick search in our manual database or a Google search. Once you find the manual, print and keep it. I guarantee that you will use it in the future. If it’s an antique of a filter, you may want to call the manufacturer.

Inside the manual, the filter specs typically include the flow rating, filtration area, port size, and turnover rates. The flow rating is essential because it dictates the maximum gallons per minute your filter can handle. In other words, do not go over this number. If your GPMs on the pump exceed the GPMs on your filter, sit back and analyze which one needs to be bigger, the pump, the filter, or both.

Look at the turnover rate listed on the filter. Your pool size should fit within those parameters. If they do not, you should consider purchasing a bigger filter. A properly sized filter is always larger than the gallon size of the pool. You want wriggle room in your filtration area because that way you aren’t backwashing or cleaning your cartridges every week. So, unlike your pool pump, we always recommend oversizing your filter.

Above Ground Pump Resources

Above Ground Pool Pump Buying Guide

Can I Install an Above Ground Pool Pump On an Inground Pool?

Are you still unsure which horsepower you should go with? Or, do you want to discuss replacing just your motor? Feel free to ask a question and join our discussion on our INYO POOLS FORUM.

101 thoughts on “Sizing Your Above Ground Pool Pump

  1. I have 16ft round above ground pool. I currently have 680 gal filter pump on it, but it doesn’t seem to be working very well. Do I need a bigger pump? If so, what size do you recommend?

  2. Hello, I have an 18×33 Oval Pool 48 inch walls. We currently have a 1.5 hp pump that is very old. Should I go to a 2 hp pump instead? what size filter what I need? Also do you recommend sand or cartridge?

    1. Did the 1.5 HP pump do the job? If so, keep the same HP. Unless you have a reason for changing the HP, there’s no need to do it.

      What’s the size of your current filter? Use that as a baseline for future filter replacements. If you go with a bigger filter, you can go longer between cleaning.

      The cartridge is more user-friendly but more expensive to operate of the filter’s lifespan due to the replacement cartridge. Sand is also somewhat easy to maintain, but backwashing wastes water.

    2. Hello I’m new to pools and I bought a 24′ x 52″ Above ground what pump size and filter do I need to be able to run a pool cleaner sweeper

  3. I have a 18×48 above ground round what size pump would I need. Next year I am upgrading to a 20 by 52 round what size pump would I need that with a 1.5 be enough for both pools

  4. I have 14ft round pool my pump/filter is not keeping up. Would a 1 hp pump/filter work ok or would it be to strong?

  5. Question: I have a Hi-Flo 1.5 HP pump for my 33’ round, 52” wall above-ground pool. I am looking to replace it in the spring. Should I upgrade to a 2.0 HP? Thanks for your input. (Clevetroit-at-g-mail-dot-com)

  6. The gallon chart doesn’t seem to account for wall space used up by air in top or the floor underneath. For instance, I have a 52″ pool but it’s really only 44″ deep, so just around 15600 gallons, right?

  7. My pool is 15 FOOT X 42 INCHES does anyone know what type or what size or kind is pump I will need I need help ASAP having big issues with this pool

    1. I have Summer Waves 18 ft Dark Double Rattan Crystal Vue Elite Frame Pool, Round what size pump do I need?

  8. I have a 22 foot pool, about 11,500 gallons. But I bought a 1.5Hp pump/filter that I cant return.
    There is a .4hp pump that comes with the pool. Can I use my bigger pump on this pool, or am I looking at damaging the pump?

    1. You should be able to use the larger pump and filter system if you use the correct PVC. You will want to get heavy-duty flex PVC or hard pipe, as the hoses that came with that smaller pump will probably collapse under the higher pressure.

  9. I have a 16’x32’x52″ intex pool, it has a 16″ sand filter holds 120# of sand. I need to replace the pump, What size pump will go with that sand filter ?

  10. I have a 24ft x 48″ round above ground pool, I have a 3hp pool pump, no filter. Would like to use a sand filter. I believe the pool holds around 15k gallons of water. Is a 3hp pump too much and what kind of filter do I need to go with it?

  11. I have a 24, 500 gallon 16 x 34 rectangle below ground/ vinyl liner 8 foot depth pool and a Pentair 1.5 HP single speed pump. Is the pump sufficient or undersized?

  12. I have a 14ft x 42 inch pool. Is a 1.5hp and 50 GPM filter. I think thats overkill but will it hurt the pool?

    1. The pump/filter combo will not hurt the pool. It will allow you to turn over the water quicker, which means you don’t have to run the pump as long. It may save you some money in the longterm if you schedule the runtimes right.

  13. Hi,

    So i have a 15 round pool and i bought a hayward 1.5 pump hp is that okay i felt like i was struggling with my 1hp pump last year?

    1. HI tracy,
      I have the coleman pool 22x12x52′. I need to replace my pump and filter… would a 1.5HP pump work? what did you end up getting?

  14. Is there any difference in recommendations when I have an above ground pool (24’ round, 48” deep) but it’s nearly completely buried and all the plumbing from the filter to the pool is buried? We just bought this house and it came with a 3/4 HP and a 19” (?) sand filter.

  15. We have a 54 inch tall x 27 foot round above ground pool. We have a pump and sand filter unit.
    I would like to change the top mount multivalve.
    I may have to buy a new pump also. Any recommendations and info on what to purchase ?

  16. I have a new 15ft round intex above ground Pool. Got a Hayward matrix 1hp pump and t180 sand filter. The pool is 1 1/4 “ out and in the sand filter is 1 1/2” and the pump looks like 2 1/4” wher should I step up the connect to the pump and back to the pool

    1. I have a 12X22 foot oval pool and the pump it came with keeps overheating and shutting off. What size of pump should I buy?

    2. I have a intex pool I purchased a sand filter 37gpm but it seems like my return is not giving me a good return doesn’t even reach to the middle of the pool it’s a 22×52 any suggestions.

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