Pressure Washer GPM Explained – Beginner’s Guide

Published by: | Updated: January 21, 2023
JCS Refresh What Is Gpm For Pressure Washer

Fun fact: pressure washers use 50% to 70% less water than your garden hose when for cleaning. 

Not many homeowners realize this, but in addition to getting your time back, pressure washers save money by reducing water usage. 

But how?

Better GPM ratings mean more savings, and it’s better for the environment, too.

In this article, we’ll go over GPM in further detail: what it means, how to spot a unit with a good GPM, and answers to common questions.

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About The Author

Meet the expert behind this article. 



Co-owner & Service Director

Hey there, I’m Cody. 

A decade of residential and commercial pressure washing led me to start JCS Refresh. Now I can share my knowledge with folks like you. 

Reading from Washington State?

We offer a variety of services and service the many cities near Seattle. Contact our team for a free quote.

Quick Answer

So what does GPM mean on a pressure washer? 

GPM stands for Gallons Per Minute, the flow rate of water from a pressure washer.

The flow rate determines the performance and, in many ways, the cleaning quality of the pressure washer. 

In general, it measures the amount of water that flows out of the unit every minute, with a higher flow rate allowing you to clean the surface faster.

How many gallons per minute does a pressure washer use?

GPM varys depending on the brand and model. 

However, a typical pressure washer will use between 2 and 4 GPM or 120 to 240 gallons per hour under continuous flow.

That may surprise you, but it’s not much, mainly when cleaning, similar to 2 to 3 full baths of water for every 1 hour of pressure washer usage.

JCS Refresh - What Is Gpm For Pressure Washer - How many gallons per minute does a pressure washer use
Let's tackle years of filth

What is the best GPM for a pressure washer?

The answer to this differs depending on the job and the required degree of effort. 

But, in general, higher GPM means higher efficiency, but that’s not the only metric to consider.

Higher GPM means more water use per minute. Yes, but greater GPM cleans quicker. If you do it in less time, you use less water. 

2.0 to 2.5 GPM is a good range to start with when looking for pressure washers. These machines will clean efficiently, yet are still affordable for most homeowners.

After JCS Refresh washed away all that grime.

should I care about PSI?

Another factor to consider is the PSI, which stands for Pounds per Square Inch. 

PSI relates to the amount of pressure the machine produces or its power to remove tough dirt and grime.

Is PSI or GPM more important for a pressure washer?

One is not necessarily better than the other. A good pressure washer must utilize PSI and GPM values to do the work successfully and efficiently.

PSI offers power, which is useful when removing stubborn gums or stains.

GPM represents speed. Consider cleaning driveways or decks and patios. You don’t want to spend extra time cleaning. GPM cleans them as quickly as possible for you

To learn more about how these two, read our comparison guide: PSI vs. GPM

JCS Refresh - What Is Gpm For Pressure Washer - is PSI or GPM better

What are pressure washer cleaning units?

Cleaning Units (CU) are used to assess the performance of a pressure washer.




Cleaning Units


Smaller Jobs




Car washing and smaller projects

Medium Jobs




Cleaning decks, siding, and just about any residential job

Large Jobs




Driveways and larger residential jobs

Commerical Medium




Prepping wood and cleaning concrete

Commerical Large




Stripping paint and cleaning larger jobs

Original chart provided by Powermate.

Pressure cleaning units are found by multiplying PSI by GPM. 

This means that even if one is higher and the other is lower, it might suggest that the machine is more powerful than it is quick, or vice versa, but a good result for the cleaning units reflects its overall efficiency.

Frequently asked questions

The following are some frequently asked questions that homeowners have about GPM.

If you have a question that isn’t answered here, please contact us, and someone from our team will get back to you.

Is 1.2 GPM good for a pressure washer?

1.2 GPM is on the low end, but it is still effective for smaller projects, such as car washing. However, we do not suggest this for more extensive jobs.

How much GPM do I need to pressure wash my driveway?

A flow rate of at least 3 to 4 gallons per minute will do the trick, but we suggest that the machine also have at least 3000 PSI to clean driveways effectively.

Do I need a high GPM pressure washer?

Not necessarily, if you’re doing minor cleaning tasks. However, you will need a pressure washer with a high GPM for larger areas.

What is a good GPM flow rate?

A starting flow rate of 2.0 to 2.5 GPM is ideal; aim for a higher GPM when cleaning bigger spaces.

JCS Refresh - What Is Gpm For Pressure Washer - FAQ 2


In a pressure washer, one should not depend solely on the PSI. GPM must also be considered, and remember that one is not superior to the other. You want a pressure washer that strikes a good balance between the two. 

Thanks for reading!