Use our high-pressure nozzle calculator to discover the optimal tip size to use with your pressure washer:
Pressure Washer Nozzle Size Calculator
Enter your machine’s flow (GPM) and working pressure (PSI). We’ll calculate the correct nozzle orifice size
Tip naming: choose your spray angle (0°, 15°, 25°, 40°, or 65° soap) with the same orifice number. Example: a 25° tip with a 3.5 orifice is often labeled 25035.
Safety: verify ratings for gun, hose, and fittings. Results assume clean water and a healthy pump.
Pressure Washer Nozzle Size Calculator: Get the Right Tip in Seconds
Use the free pressure washer nozzle size calculator above to find the correct orifice size for your machine. Enter your GPM and PSI, press Calculate, and you’ll get the optimal nozzle size.
How the calculator works
Behind the scenes, the calculator applies the standard sizing formula used across the industry: Nozzle Size = GPM × √(4000 ÷ PSI). Example: 4.0 GPM at 3000 PSI ≈ 4.62 → stock a 4.5 orifice. Another: 5.5 GPM at 2500 PSI ≈ 6.96 → stock a 7.0 orifice.
This returns the orifice number. Your spray angle (0°, 15°, 25°, 40°, 65°) is selected separately, but it uses the same orifice size. For a quick refresher on patterns, colors, and tip codes, see our pressure washer nozzle chart — what the colors and numbers really mean.
When to choose different pressure washer nozzle sizes
- You want full rated pressure: Use the calculator’s result (closest stocked size) to match your target PSI.
- More flow / gentler cleaning: Go one size up in orifice (pressure drops).
- More bite on tough grime: Go one size down (pressure increases), but confirm your gun, hose, and pump are rated for the load.
If you’re still learning how different tips behave, our deep dive explains spray patterns, impact, and applications: Ultimate Guide to High-Pressure Cleaning Nozzles.
What size pressure washer nozzle do I need?
The most reliable method is to use the calculator with the GPM and PSI on your pressure washer’s spec plate. Choose the closest stocked orifice to the exact result. That size number then applies across all tip styles—quick-connect fans, turbo/rotary nozzles, and threaded WashJet-style tips—so you can pick the spray pattern for the job while keeping the correct orifice.
What happens if the nozzle is the wrong size?
An undersized nozzle spikes pressure (risking pump wear, relief valve chatter, and shorter component life). An oversized nozzle drops pressure (poor cleaning, wasted time, extra passes). Get the full rundown here: What happens if a pressure washer nozzle is the wrong size?
Shop by tip style (matched to your calculated size)
- Quick-connect pressure washer nozzles — common fan angles for everyday cleaning.
- Rotating turbo nozzles — concentrated impact that “spins” for faster removal.
- Stainless threaded nozzles — MEG/WEG/IMEG/HVSS tips for industrial wands and lances.
Tips for accurate results
- Verify your machine’s actual GPM and PSI (pump label or manual).
- Confirm component ratings (gun, hose, lance, fittings) before sizing down.
- Replace worn tips—erosion enlarges the orifice and quietly drops your working pressure.
FAQs
How do I read pressure washer nozzle sizes?
The size is the orifice number (e.g., 4.5). Tip codes combine angle+size (e.g., 25045 = 25° fan with a 4.5 orifice). See the nozzle chart for colors, angles, and codes.
Does spray angle change the nozzle size?
No. Angle controls pattern width, but the orifice number stays the same across 0°, 15°, 25°, 40°, and 65° tips.
Will a turbo nozzle use the same size?
Yes—the internal orifice must match your calculated size. Select the orifice first, then the turbo model and flow rating.
