Choosing Cleaning Power: PSI and GPM

Different pressure washer jobs require a different amount of cleaning power. A pressure washer's cleaning power is measured by a PSI (pounds per square inch) and GPM (gallons per minute) rating. PSI measures the pressure, or cleaning force, of water created through the pressure washer. Use the PSI rating to help you determine how powerful the water stream will be. The GPM measures the volume of water delivered through the pressure washer. This number will help you determine how fast the pressure washer will clean, and how effectively it will rinse away debris.

Tip: Calculate the cleaning power of a pressure washer by multiplying its PSI by its GPM (PSI x GPM). This will help you compare models so you can choose one that will be up to the job.