Pressure Washer Flow Rate Explained

Pressure-washer flow rate is the volume of water the machine can deliver, normally shown as litres per hour (L/h). It matters because pressure loosens dirt while water carries it away.

A high bar figure with modest flow may be less practical across a large patio than the headline suggests.

How to compare L/h

Use manufacturer maximum-flow figures consistently. Compact domestic machines may publish figures in the low-to-mid 300L/h range, while larger domestic models often move into the 400L/h range.

This is not a universal quality scale: the right flow depends on the job, water supply, nozzle and how long the work lasts.

When extra flow helps

Larger patios, driveways and heavier dirt tend to benefit because more water can rinse a wider working area. For a bike or occasional furniture cleaning, lower flow may be perfectly adequate and easier to store.

Check the complete system

The supply tap and hose must meet the manual’s requirements. Actual performance can differ from a published maximum. Hose reach, pressure control and attachments can have a larger practical effect than a small difference in L/h.

Use the pressure-washer finder to set a flow minimum from the surface area and dirt level. Pair this guide with pressure washer bar explained.

Nilfisk and Bosch publish pressure and flow together on their official product pages, including the Nilfisk Core range.