GPM vs. PSI in Pressure Washers. What’s The Difference?

gallons per minute vs pressure per square inch gpm vs psi in pressure washers

GPM vs. PSI in Pressure Washers?

Pressure washers are must-have tools for industrial, commercial, and agricultural purposes. They make cleaning tasks quicker and easier while providing an efficient and cost-effective solution. However, when shopping for pressure washers, you’ll encounter two main stats: GPM (Gallons per Minute) and PSI (Pressure per Square Inch). Understanding GPM vs. PSI metrics is crucial to determining which pressure washer will meet your specific needs. In this blog post, we’ll discuss the difference between GPM and PSI and what you need to consider when choosing the right pressure washer for your needs.

GPM in Pressure Washers

gallons per minute in pressure washers

Gallons per Minute (GPM) is one of the primary metrics that determine the water flow rate in a pressure washer. It indicates the amount of water that the pressure washer can deliver per minute. The higher the GPM, the more cleaning power the pressure washer has. With a high GPM rating, you can clean larger areas in a shorter amount of time. Most industrial-grade pressure washers have a GPM rating ranging from 2.5 to 10 GPM, but Alkota is able to custom design pressure washers in GPM up to 25 GPM.

Do note that the higher the GPM, the more power you will need to drive the pump, and you may end up sacrificing pressure for higher flow rates, which is not always a bad trade-off, as the advantage can be quicker cleaning.

PSI in Pressure Washers

pressure per square inch in pressure washers

The other primary metric that you should consider when looking for a pressure washer is the Pressure per Square Inch (PSI). PSI indicates the amount of cleaning power the pressure washer will exert on the surface you are cleaning. A higher PSI rating means that the pressure washer will provide more power to clean away tough stains and dirt. However, a high PSI rating does not necessarily translate to a better cleaning job, as you will still need adequate water flow to rinse away the dirt. A PSI rating of 3,000 to 5,000 PSI is generally recommended for most commercial applications. Again, Alkota has pressure washers ranging from 1,500 – 5,000 PSI with custom options for even more pressure.

So What’s More Important? GPM or PSI?

When selecting the right pressure washer, you need to consider both GPM and PSI. If you need to clean a large area, you should opt for a high GPM rating to expedite the cleaning process. However, a high PSI rating will be more effective if you’re cleaning areas with stubborn stains and heavy dirt buildup. For most commercial applications, pressure washers with a GPM of 3.5 to 5.0 and a PSI of 3,000 to 4,000 are ideal.

The basic rule of thumb is: More PSI, more knock-down, more GPM fast cleaning of larger areas.

In addition to GPM and PSI ratings, you also need to look at the engine horsepower, pump quality. The engine is critical as it powers the high-pressure pump that delivers water through the spray wand. A high-quality pump ensures consistent water flow and higher pressure output.


When it comes to pressure washers, both GPM and PSI are vital metrics to consider. They work together to provide efficient and effective cleaning power, which is essential for commercial and industrial applications. Choosing the right pressure washer involves selecting the right combination of GPM and PSI, along with other features such as engine horsepower and pump quality. We hope that this blog post has helped you to understand the difference between GPM and PSI and how to choose the right pressure washer for your needs.

If you have additional questions or want to demo some different PSI and GPM combination, we recommend reaching out to your local Alkota Distributor for more information.

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