Sprayer Nozzle Size Guide

When it comes to spraying, nozzle size is one of the most important factors that determines how much liquid you apply, what your droplets look like, and ultimately, how effective your application is. Yet it’s also one of the most misunderstood topics.

This guide breaks down what nozzle size means, why it matters, and how to size nozzles correctly so you get consistent results every time you spray.

What Is Nozzle Size?

Spray nozzle size refers to the size of the opening through which the liquid passes in the nozzle tip. People might say ‘nozzle size’, ‘tip size’, ‘nozzle capacity’, or ‘orifice size’, but they all mean the same thing. So basically, the terms nozzle size and orifice are synonymous.

Nozzle Size Basics:

• A smaller orifice restricts flow, delivering less volume per minute.
• A larger orifice allows more flow, delivering higher volumes.

Manufacturers use a numbering system to indicate nozzle size. Because most brands follow ASABE standards, the last two digits of the nozzle number generally correspond to flow rate. For example, a TeeJet XR 11002:

• “110” = spray angle (110°)
• “02” = orifice size, flowing 0.2 gallons per minute (GPM) at 40 PSI

Generally speaking, all flat fan sprayer nozzles follow this sizing pattern. The different sizes follow a color code so that they can be easily identified across different nozzle families and nozzle brands. For example, in the image below, you can see five different nozzle types from various brands, yet they are all red nozzles. Meaning they will all produce the same GPM flow rate at any given pressure.

If you would like to learn more, I detail the full color code for spray nozzles in this guide.

It is vital to note that this color and nozzle size code only covers flat fan sprayer nozzles, not power washer nozzles, flood nozzles, or adjustable nozzles.

How Nozzle Size Is Determined

Nozzle size is tied to three things:

1. Orifice diameter – the physical opening in the nozzle
2. Operating pressure (PSI) – raising pressure increases flow and decreases droplet size
3. Flow capacity (GPM) – measured at 40 PSI for standard nozzles

For example, A TeeJet XR 11002 flows 0.2 GPM at 40 PSI. If you raise the pressure to 60 PSI, it will flow about 0.24 GPM. This information is available in a spray nozzle chart provided by the manufacturer. That’s why nozzle charts and calculators are essential—pressure and orifice size always work together.

Why Nozzle Size Matters

Choosing the wrong nozzle size can cause big problems:

• Coverage errors – too small a nozzle under-applies product, too large over-applies
• Droplet size – small orifices create finer droplets, which drift more; large orifices produce coarse droplets, which may reduce coverage
• System design – your pump and regulator need to handle the total flow demand of the nozzle set

Getting nozzle size right ensures you hit your target rate, minimize drift, and maximize product performance.

How to Size Nozzles Correctly

Sizing nozzles doesn’t have to be complicated. Follow this simple process:

1. Determine your target application rate (GPA).
   >Example: 15 GPA for herbicide.
2. Know your ground speed (MPH).
   >Example: 8 MPH.
3. Measure nozzle spacing (inches between nozzles on the boom).
   >Example: 20 inches.
4. Use the formula: GPM = [(GPA × MPH × W)/5940]
   where W = nozzle spacing in inches.
   In this case: GPM = [(15 × 8 × 20)/5940] = 0.40 GPM
5. Check nozzle charts to see which nozzle size delivers ~0.40 GPM in your desired pressure range.

👉 In this example, a TeeJet XR 11004 (0.40 GPM at 40 PSI) would work, assuming we are comfortable with the droplet size and pattern produced by this nozzle type.

Resource: Try our Sprayer Nozzle GPM Calculator to size nozzles instantly without the math.

Common Mistakes When Choosing Nozzle Size

• Selecting based only on pressure. Remember that flow rate (GPM) is the primary driver, not PSI.
• Ignoring travel speed. Changing from 6 to 10 MPH can completely change your GPA.
• Using worn nozzles. After 10% wear, nozzles flow higher than spec, leading to over-application.

Frequently Asked Questions About Nozzle Size

Q: What nozzle size should I use for spraying herbicide vs. fertilizer?

A: The nozzle size that you use will depend on the rate you want to apply. Whether herbicides or fertilizer, you need to determine the gallons per minute flow you need per nozzle to achieve your desired application rate. For more details, check out my guide on nozzle selection.

Always check your product label for recommended droplet size and pressure range.

Q: Is there a nozzle size chart by color?

A: Yes — most agricultural nozzles follow ASABE color standards. Each color corresponds to a flow rate at 40 PSI (e.g., yellow = 02, blue = 03, red = 04). See our full Nozzle Color Code Chart to compare flow rates and typical uses.

Q: How does nozzle size affect droplet size and drift?

A: Smaller nozzles (like 01 or 02) typically produce finer droplets, which can drift more easily in the wind.
Larger nozzles (04, 05, 06) typically produce coarser droplets that are less prone to drift but may reduce leaf coverage.

Within a single nozzle family, the difference in droplet size moving from smaller orifices to larger ones may be minimal, but the trend remains the same: smaller nozzles tend to produce finer droplets. You can use our Droplet Size Viewer to see how nozzle size and pressure affect droplet class.

Q: Can I use the same size nozzles for different products?

You can, but it may not be ideal. Different pesticides or fertilizers will have varying application rates. Thus, a nozzle designed for applying a herbicide rate may be too small (or large) for a fertilizer or fungicide, etc.

Q: How do I know what nozzles are on my sprayer now?

Check the number stamped or printed on the nozzle body — for example, “XR11003” or “AI11005VS.”
If markings are worn off, match them visually to your Nozzle Color Chart or measure flow at 40 PSI to determine size.

You can also do a catch test to determine the size of your nozzles. You can read more on how to do that in this guide.

Q: Does nozzle size change if I spray faster or slower?

Nozzle size stays the same — but your application rate (GPA) changes with speed. If you drive faster, you’ll apply less per acre. Slower = more per acre. Use our GPM-to-GPA Calculator to find the right speed and nozzle combination.

Q: Can I just buy bigger nozzles to cover more area?

Not necessarily. Larger nozzles allow higher flow, but that doesn’t automatically mean more coverage. If you maintain the same speed, then you will actually cover less area, but you’ll use more chemical per acre and may waste product. If you speed up, you can cover the area faster, but you will empty your tank sooner.

Conclusion

Nozzle size = orifice size. The two terms are interchangeable, and they’re the key to getting spray applications right. By taking the time to size your nozzles based on GPA, speed, and spacing, you’ll save money, reduce drift, and get better results from every tank load.

Before your next application, double-check your nozzles with a chart or calculator—you might be surprised how much difference the right size makes.