pool pump size - Classic Marcite

What Pool Pump Size Do I Need: A Sizing Guide

by | Jun 23, 2023

Have lots of pool-related questions but no answers? Contact your nearest Classic Marcite team to get all the info you need. 

Choosing the right pool pump size can feel challenging, especially if you don’t know how a pool pump works. It’s tempting to go bigger, but in some cases, doing so just means you’re spending money on power that you don’t need. 

We compiled this pool pump size guide to help pool owners across Florida get the perfect pump for their swimming pool.

Horsepower vs. Water Flow

A common misconception is that you should use the pool pump’s HP (horsepower) to decide which one is best for your pool. However, you should rather use a measurement that will give you a much better estimation of effectiveness: gallons per minute (GPM). This directly shows you how many gallons of water a pump can move in a given timeframe, which is ultimately more relevant to your needs.

How to Pick Your Perfect Pool Pump Size

It may be tempting to simply estimate your pool pump based on an average size, but spending a bit of time understanding your precise needs will yield better results as you’ll have a pool pump ideally suited to your pool and cleaning needs. 

1. Calculate Your Pool Volume

If you don’t know your pool’s volume offhand, the simplest way to calculate it is with an online calculator. All you need is the length, width, and average depth to get a relatively accurate measurement. Best of all, most calculators will have formulas for oddly-shaped pools, so you don’t need to worry too hard about the math. 

2. Decide How Long You’re Willing to Have Your Pump Running

The biggest difference between pump sizes is how long they take to move all the water in a particular pool. You can still get away with a smaller pump in a larger pool — it will just take ages to complete a cycle. 

The first step to identifying your GPM is how long you want one cycle to take. A good rule of thumb is three to four hours, as that lets you get in multiple cleans during peak season, and you’ll only need to run your pump for a few hours per day in the off-season. You can then plug that number into the following formula to get your ideal GPM:

GPM = Pool volume/hours/60 

3. Identify the Pool Filter Flow Rate

Your pump and filter need to have the same flow rate to work effectively. If your filter has a lower flow rate, it will create extra pressure due to water accumulation, leading to more wear and tear on both the pump and filter. 

It’s a good idea to get a pool filter with a slightly higher GPH than the pool pump size, which alleviates any potential filtration efficiency issues. 

At Classic Marcite, we love helping pool owners get answers to pressing questions like “What size pool filter do I need?” or “Should I resurface my pool?” Contact our Classic Marcite team o schedule a pool consultation by calling 407-521-6260 for Orlando or 904-448-4150 for Jacksonville, FL.

Now Serving St. Augustine

We’re excited to announce that Classic Marcite now extends its pool maintenance and renovation services to the St. Augustine area. Residents in St. Augustine can now rely on our expert team for efficient and professional pool care, including the crucial task of changing the sand in your pool filter. Trust us to keep your pool in pristine condition.

About Mike Folta
Mike Folta has served the clients of Classic Marcite for more than 15 years. He has 20+ years in the pool industry servicing large hotels and theme parks in the Greater Orlando area, as well as expertly turning backyard pools into an island oasis.