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.


21 thoughts on “Sizing Your Above Ground Pool Pump

    1. You’re pool holds less than 15,300 gallons. So by their calculations above, a 1hp should work. But it’s the GPM that really matter, and that’s a little more complicated. I have a 1hp motor that came on my 24’/52” round pool and it can’t keep up with the algae here in wet lower Alabama.

  1. I just bought a pump that is for a pool up to 7000 gallons but my pool is 7646 gallons with it work or should I just send the pump back please help I need to know asap

  2. I have a D fliter for my pool it’s 14” 33
    But domestic seem to be moving h the water. So what size is the next size up.

  3. I have a 15’x48″ round above ground pool and I found a good deal on a Intex 2100 GPH Above Ground Pool Sand Filter Pump with Automatic Timer | 26645EG. Would that be a good filter or should I step up to the 3000 GPH?

  4. I just bought the Coleman above ground pool that is 22×52 and the pump that came with it seems ok, but not great enough for the size pool. I just don’t feel that it circulates the water well enough. What size pump should I upgrade to? Any recommendations on brand ? Please help! I live in Alabama and the past few weeks we have had a lot of rain and I’m having to shock the pool more often and I think that because the pump isn’t big enough is part of the problem.

      1. Matthew,
        I have a Coleman 26 x 52 which holds 15000 gallons of water. The pump that came with it can not keep up. Cleaning the pool is a chore! What size pump should we get? We are thinking the sand pump.
        Thank you. Vanessa

  5. 18×9 54 inches deep want to add a salt to chlorine converter to my sand filter pump. What size should I get? I don’t see it on the chart

  6. Matthew,
    I have a Coleman 26 x 52 which holds 15000 gallons of water. The pump that came with it can not keep up. Cleaning the pool is a chore! What size pump should we get? We are thinking the sand pump.
    Thank you. Vanessa

  7. I can’t keep the algea (green) hues out of my pool unless the Chlorine is to high to swim. I change my filter weekly because they will not last more than that. I think we have a pump too small but my husband thinks it wouldn’t help. 18×48 above ground pool

    1. If your pump can’t turnover the water enough to properly distribute the chlorine then that is a reasonable explanation for your algae issues. For a pool that size, a 1 HP pump would be necessary. What do you currently have?

  8. We have an 18×33 48” high oval pool. Current filter is Hayward ProSeries S180T. 150 lbs sand. The pump just went out (was original from when house was purchased). It was a Sta-rite ABG4E-2A4. 1 HP.

    I run the pump a lot. 10-12 hours per day. Am thinking I’d like to stay with Hayward so pump and filter are on same manufacturer and easier to keep up with any parts.

    Is there any problems with bumping up to a 1.5 Hp and is there any other brands I should consider and what would the reasons be? Am currently considering Hayward power-flo LX….

    Any advice would be great! Thank you 😊

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