Spray Nozzle Chart (ISO Colour Code and Flow)

This spray nozzle chart is a free calculator that shows how much liquid a nozzle sprays and the application rate that results, in gallons per acre or litres per hectare. It is built on the ISO colour code, so it works for any nozzle that follows ISO 10625, from the orange 01 up to the yellow-green 15.

You can enter a nozzle size you already have to get its flow and rate, or enter a target rate to find the smallest size that reaches it and the pressure to run. The tool runs in your browser, and there is no sign-up. Results are estimates, so check them against your real nozzles.

How to use the Spray Nozzle Chart

1. In “What do you want to work out?”, choose “Flow and rate for a nozzle size I have” or “Nozzle size for a target rate”.
2. For the flow mode, pick your nozzle in “Nozzle size (ISO colour code)”.
3. Enter “Spray pressure” and choose psi, bar or kPa as the unit.
4. Enter “Ground speed” (mph or km/h) and “Nozzle spacing” (in or cm).
5. Read “Nozzle size”, “Flow per nozzle” and “Application rate”. The metric figures are shown beside the US ones, and the tables switch to L/min and L/ha when you pick bar or kPa.
6. For the target mode, enter “Target application rate” in gal/ac or L/ha.
7. Set “Lowest pressure you will run” and “Highest pressure you will run”. The defaults are 30 and 60 psi.
8. Read “Smallest size that reaches the rate”, “Pressure for that size to hit the rate”, the rates at the lowest and highest pressure, and the next size up if it also fits. Pay attention to any warning.

The two tables under the results always show flow for all 13 sizes and the application rate for every size and pressure. The preset buttons fill in example inputs you can change. “How it was calculated” shows each step with your numbers. You can use “Copy result”, “Copy link” (the link keeps all your inputs), “Print / save as PDF” or “Reset”.

What is the spray nozzle colour chart (ISO colour code)?

The spray nozzle colour chart gives each nozzle size a colour, and the colour is tied to flow rate, not droplet size. The size number divided by 10 is the US flow in gpm at 40 psi, so a 04 gives 0.40 gpm at 40 psi. The 13 sizes run from 01 orange, 015 green, 02 yellow, 025 violet (also called lilac), 03 blue, 035 purple-red, 04 red, 05 brown, 06 grey, 08 white and 10 light blue to 12 raspberry red and 15 yellow-green.

Metric flows are measured at 3 bar and come from ISO 10625:2018 Table 1. They run from 0.4 L/min for size 01 to 6.0 L/min for size 15. The colour code is the same across makers that follow ISO 10625. It does not tell you droplet size, spray angle or drift ratings, which depend on the nozzle type and the maker’s chart.

How does pressure change nozzle flow?

Flow rises with the square root of pressure. The rule is Q2 = Q1 × √(P2 ÷ P1), from K-State MF3178 Equation 2. The reference pressure is 40 psi for US sizes and 300 kPa (3 bar) for metric sizes.

Because of the square root, doubling the pressure raises flow by only about 41 percent (the square root of 2). Pressure is therefore a weak way to change your rate. Changing the nozzle size or the ground speed has a much larger effect.

How do I read the application rate part of the chart?

The second table gives the application rate for every size and pressure at the ground speed and nozzle spacing you entered. Find your size in the first column and your pressure along the top. With the defaults, a size 04 at 40 psi, 8 mph and 20 in spacing applies 14.85 gal/acre, which the table rounds to 14.8.

Speed and spacing change every cell. The rate falls as you drive faster or space the nozzles wider: the same 04 at 40 psi and 5 mph on 20 in spacing applies 23.8 gal/acre. Use the label rate as your target, and check the nozzle maker’s chart for droplet size and drift limits, which this tool does not give.

Sources

• ISO 10625:2018, Table 1 (public preview) — size codes, colours and flow in L/min at 300 kPa (3 bar)
• Kansas State University MF3178, Agricultural Spray Nozzles: Selection and Sizing — nozzle number = flow in gpm at 40 psi, nozzle gpm = mph × spacing × GPA ÷ 5,940, flow varies with the square root of pressure, usual flat-fan pressure ranges
• University of Kentucky AGR-239 — GPA = 5,940 × GPM ÷ (MPH × spacing in inches) and its metric form

Worked examples

Calculated by the tool above with these values.

Frequently asked questions

What colour is a 04 / 03 / 02 nozzle and how many gpm is it?

A 04 is red and gives 0.40 gpm at 40 psi, or 1.6 L/min at 3 bar. A 03 is blue at 0.30 gpm (1.2 L/min at 3 bar). A 02 is yellow at 0.20 gpm (0.8 L/min at 3 bar).

How much does a nozzle spray at 20, 30, 40 and 60 psi?

It depends on the size. A size 04 sprays 0.283 gpm at 20 psi, 0.346 gpm at 30 psi, 0.400 gpm at 40 psi and 0.490 gpm at 60 psi. The tool shows the same figures for all 13 sizes, along with 50 psi.

How do I find the nozzle size for a target gallons per acre?

Choose “Nozzle size for a target rate” and enter your target rate, ground speed, nozzle spacing, and the lowest and highest pressure you will run. The tool works out the flow each nozzle needs, then gives the smallest size that reaches it and the pressure at which that size gives your exact rate.

What is the formula for gallons per acre from nozzle flow?

The formula is GPA = 5,940 × GPM ÷ (MPH × nozzle spacing in inches). For example, a 04 at 40 psi on 20 in spacing at 8 mph gives 5,940 × 0.4 ÷ (8 × 20) = 14.85 gal/acre. The metric version is L/ha = 60,000 × L/min ÷ (km/h × spacing in cm).

Is there a metric nozzle chart in L/min and bar?

Yes. Choose bar or kPa as the pressure unit and the tables switch to L/min and L/ha. The metric reference is 3 bar (300 kPa), and the pressure tables run from 2 to 6 bar. For example, 100 L/ha at 12 km/h and 50 cm needs 1.0 L/min per nozzle, which is size 025 (violet) at exactly 3 bar.

Is the calculator free, and is anything I type uploaded?

Yes. The calculator is free, runs in your browser, needs no sign-up, and nothing you type is uploaded. Results are estimates. New nozzles can vary by ±5 percent, and wear changes flow over time, so catch-test your nozzles. The sprayer calibration calculator can help with that.

Related tools

• Sprayer Calibration Calculator: use it to check your real sprayer output after catch-testing the nozzles.
• Acre per Hour Calculator: use it to estimate how many acres you cover in an hour at a given speed and width.
• Fertilizer Calculator: use it to work out fertilizer amounts for a field.
• Seeding Rate Calculator: use it to set seed quantities per acre or hectare.
• Acreage Calculator: use it to work out the area of a field before you plan spraying.
• All calculators: use it to browse every tool on the site.