What Is Gpm Pressure Washer

PressuWhat Is Gpm Pressure Washerre washers are a blessing for cleaning vast areas and deep stains. With their use, you can clean the surface in minutes. That was a job of hours with the brush and bucket. Moreover, they provide better cleaning and require less effort. In the specification of the pressure washer, one thing would go through your eyes, and it is the GPM. It is most commonly written alongside the Psi of the pressure washer. In this article, we will discuss in detail the GPM of the pressure washer, its importance, and which GPM pressure washer would be suitable for you.

What Is A GPM Pressure Washer?

GPM is the unit of volume flow rate, and the complete form of GPM is Gallon Per Minute.  Basically the GPM is the amount of water discharged from the nozzle of the water in a minute, measured in Gallons. The term GPM is different from Psi or pressure but is directly proportional to it. High pressure is essential, but GPM plays the primary role in cleaning the surface. Water is a universal cleaning agent, and more water will quickly remove the debris and dirt.

GPM is a crucial factor to consider in purchasing a pressure washer. Generally, the pressure washer with high pressure has higher GPM, but it is necessary to consider both.

The technician combines the pressure and its flow rate capacity to have a general idea about the cleaning effect.

Consider two pressure washers, both having the nozzle pressure of 2500 psi, but the first one has a flow rate of 1 GPM, and the second one has a flow rate of 2 GPM. Both the pressure washers have the same Psi, but the pressure washer with the higher flow rate will clean the area half the time.

On the other hand, if both the pressure washers have the same flow rate, the first pressure washer provides double pressure compared to the second pressure washer. For example, the first pressure washer offers 3000 psi with a 1.5 GPM flow rate, and the second one has 1500 psi with 1.5 GPM. The pressure washer with 3000 psi will clean the surface twice as fast as the pressure washer with 1500 psi, provided that the flow rate in both of them is the same.

To have an idea about the cleaning effects, the technicians have developed a team known as the cleaning unit. The cleaning crew is the product of the pressure and the flow rate. The CU is the correct quantity to determine the cleaning capacity of the pressure washer.

It can be found as

CU = Pressure (psi) * Flow rate (GPM)

From this formula, the pressure washer with the flow rate of 1.5 GPM and pressure of 2000 psi will have a CU of 3000. It would provide the cleaning equivalent to the pressure washer having the 3000 psi and 1 GPM flow rate.

What Is GPM Good For Cleaning Surfaces?

The pressure washers are available in different GPM and Psi, but choosing the suitable pressure washer with optimum specifications is essential. Choosing the pressure washer with a low specification will result in ineffective cleaning, and choosing the pressure washer with a higher GPM will damage the surface. These are the optimum GPM range for cleaning different kinds of characters.

  • 1 to 1.5 GPM for cars and another light cleaning
  • 1.5 to 2 GPM to clean the home sidings, patios, and decks
  • 2.3 to 2.5 GPM to clean the driveway or the pavement
  • 2.5 to 2.8 GPM for professional cleaning of concrete and woods
  • 3 to 5 GPM for cleaning and removing the paint or the rust and for larger jobs


GPM and Psi are critical factors to consider in purchasing the pressure washer. GPM is the primary factor affecting the cleaning, and to have the correct interpretation of the cleaning power of the pressure washer, the product of the GPM and Psi is taken, and it is known as the cleaning unit. There are different selection criteria for GPM for other surfaces, and it is crucial to choose the most optimum to have maximum efficiency.