PSI vs. GPM – Pressure Washer Ultimate Guide

Published by: | Updated: January 21, 2023
JCS Refresh PSI vs GPM Pressure Washer

Still trying to understand the difference between PSI and GPM?

Don’t you worry! You came to the right spot. 

In this article, we will distinguish the difference between PSI and GPM as they relate to pressure washing and outline their importance.

Additionally, we’ll cover a few frequently asked questions at the end of the article to clear up any final thoughts.

Table of Contents - Click to Skip

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 service many cities in the greater Seattle area. Visit our pricing page to learn more.

What does PSI stand for? 

PSI stands for pounds per square inch. 

Commonly used for measuring pressure and representing force, PSI refers to how the intensity of pressure and can adjusted accordingly.  

The higher the PSI, the more concentrated power coming from the wand or gun. For most jobs, the appropriate range of pressure is between 2,000 and 4,000 PSI. 

However, too much pressure (PSI) can cause damage to materials if you’re not careful.

JCS Refresh - PSI vs GPM Pressure Washer

What is GPM for pressure washers? 

GPM stands for gallons per minute and refers to the flow rate of a pressure washer. 

So, the higher the GPM, the faster water will flow through the machine.  

Like PSI, high GPM machines are unsafe if not handled with care and can lead to surface damage. 

Keep these in mind before cleaning things like your deck or house

JCS Refresh - PSI vs GPM Pressure Washer (2)

What is a good GPM for a pressure washer?

Your ideal pressure washer depends on the job and how you use a pressure washer

Below is an overview of the various levels and sizes of GPM and what areas it caters to:

  • 1.4 to 1.6 GPM – used for light jobs (cleaning vehicles)
  • 1.7 to 3.0 GPM – used for light duty and domestic areas (primarily for residential)
  • 3.5 to 5 GPM – used for heavy-duty and daily needs
  • 3.5 to 9.5 GPM – used for tough and heavy jobs on farms, industrial areas, and commercial sites

GPM ranges are an important factor of projects and jobs. 

For example, 2-4 GPM is ideal for residential use. While for commercial areas, the best range is from 3-6 GPM. 

Is PSI or GPM more important for a pressure washer?

PSI and GPM are both important for pressure washers, however, GPM is more important. 

If your goal is to clean a large surface area, such as your driveway or patio, having more water (higher flow rate) will always be advantageous. 

But if you are looking for a pressure washer for light jobs and residential use, PSI is certainly a considerable factor.

JCS Refresh - PSI vs GPM Pressure Washer (3)

Frequently Asked Questions

Below are some common questions from others. 

Does GPM affect water pressure?

Yes, because GPM refers to the flow rate.

How much water does a pressure washer use?

Standard pressure washers use between 2-4 GPM or 120 to 240 gallons (545.53 to 1091.06 L) per hour. 

But this is subject to change depending on the make and model of the pressure washer.

Is 1.2 GPM good for a pressure washer?

Yes, 1.2 GPM is suitable for light-duty cleaning around your house, cleaning your car, or other vehicles. But, it’s insufficient for larger projects.

How do I increase GPM on pressure washer?

  1. First, you need to choose the proper nozzle for the specific job.
  2. Next, adjust the pressure regulator to the correct setting.
  3. Do not exceed the maximum PSI rating of the pressure washer.
  4. Lastly, follow all the manufacturer’s safety recommendations and manuals.

What PSI pressure washer is ideal to clean concrete?

Use at least 3,000 PSI to clean concrete.


Final thoughts, who wins between PSI and GPM? Well, they are both important, but GPM takes the cake.  

Thank you for staying with us until the end. We hope you enjoyed this article and can walk away with a better understanding of PSI vs GPM as it relates to pressure washing.