Nozzle Size Calculator
Enter your pressure washer's flow in GPM or L/min and its rated pressure in PSI or bar, then pick a spray angle. The calculator gives the nozzle size, the tip code, the pressure it will make and the sizes either side.
- Nozzle size
- Tip code
- Pressure
Flow and pressure are on the machine's label or in its manual.
The nozzle size is the flow it passes at 4,000 psi. Size = GPM ÷ √(PSI ÷ 4,000). A 2.5 GPM, 3,000 psi washer needs about a 2.9, so a 3.0 nozzle. With a 25° green tip, the code is 25030 and it makes about 2,780 psi.
Pressure washer nozzle chart
Nearest standard size. Search for your machine.
| GPM | 2,000 psi | 2,500 psi | 3,000 psi | 3,500 psi | 4,000 psi |
|---|---|---|---|---|---|
| 2 | 3 | 2.5 | 2.5 | 2 | 2 |
| 2.5 | 3.5 | 3 | 3 | 2.5 | 2.5 |
| 3 | 4 | 4 | 3.5 | 3 | 3 |
| 3.5 | 5 | 4.5 | 4 | 3.5 | 3.5 |
| 4 | 5.5 | 5 | 4.5 | 4.5 | 4 |
| 4.5 | 6.5 | 5.5 | 5 | 5 | 4.5 |
| 5 | 7 | 6.5 | 6 | 5.5 | 5 |
| 5.5 | 8 | 7 | 6.5 | 6 | 5.5 |
By GPM and PSI.
Flow and nozzle
3,000 psi. Slide the flow.
The tip and its spray fan are drawn with the size.
How to choose a nozzle
Machine to tip. Step through it.
GPM
From the label.
Start with the widest angle and move to narrower ones only if needed.
Narrow, medium or wide spray
Spray angles. Compare them.
Stripping.
General.
Gentle.
The colour code is the same across most brands.
Before you spray
Nozzle checks. Tick each item.
Tick each item as you go.
Never point any tip at people or pets.
What you get
Nozzle sizing. Each tile explains one result.
Nozzle.
Tip.
Made.
Sizes.
Angle.
A worn nozzle gets bigger, so pressure drops over time. Replace tips once a year if used often.
Frequently Asked Questions
No question matches that search.
What size nozzle do I need for my pressure washer?
Divide the GPM by the square root of the PSI divided by four thousand, then pick the nearest size.
What does a nozzle code like twenty-five oh thirty mean?
A twenty-five degree spray with a size three point oh orifice.
What happens if the nozzle is too small?
Pressure rises above the pump's rating, which can damage it.
What happens if the nozzle is too big?
Pressure drops and cleaning is weaker.
What do nozzle colours mean?
Red zero, yellow fifteen, green twenty-five, white forty and black for soap.
Do nozzles wear out?
Yes. The hole grows and pressure falls.
Which nozzle is best for cars?
A white forty degree tip, kept well back from the paint.
The right tip for the job
Match the nozzle to your machine and you get full cleaning power without straining the pump.
More size calculators
Each one has its own calculator, worked examples and answers to common questions.