Boom Sprayer Nozzle & The Flow Each Nozzle Needs
Calibrates herbicide
Enter target spray volume per hectare, forward speed and nozzle spacing to get the flow each nozzle must deliver — for even, accurate application.
Set up your boom sprayer
Next: pick nozzle tips rated for 1 L/min at your working pressure, then verify by catching output from a few nozzles for one minute.
Output per nozzle = (L/ha × km/h × spacing cm) ÷ 60 000. Calibrate at the real boom pressure; worn tips over-apply and drift.
Nozzle output — key facts
- Output (L/min)
- (L/ha × km/h × cm) ÷ 60000
- Inputs
- rate, speed, nozzle spacing
- Typical spacing
- 50 cm
- Pressure band
- ≈ 1.5–4 bar flat-fan
- Measure speed
- timed run, not speedometer
- Units
- L/min and US gpm
- Then
- verify with a real calibration
- Privacy
- Runs in your browser; nothing uploaded
Match the nozzle to the job, not the other way round
To apply a target spray volume per hectare with a boom sprayer, each nozzle has to deliver a set flow: output (L/min) = (L/ha × speed km/h × nozzle spacing cm) ÷ 60000. Get that flow right and matching nozzles to it at the chosen pressure gives even, accurate coverage across the whole boom. Guess it, and you either waste expensive chemical or under-dose and risk poor control and resistance.
This tool returns the required nozzle output in L/min and US gpm, the resulting spray volume per hectare, and the speed from your rate, speed and spacing — so you can choose the correct nozzle and starting pressure with confidence. Pair it with the Sprayer Calibration, Tree-Row-Volume, Spray & Tank Mix and Drone Spray tools to plan and verify the full application.
Pick the right nozzle
Know the L/min target before you buy.
Apply accurately
Hit the label rate, no over- or under-dosing.
Set the pressure
Choose a nozzle that flows it in band.
Spray evenly
Matched output across the whole boom.
Frequently Asked Questions
How is nozzle output calculated?+
Required nozzle output in litres per minute = (target volume L/ha × forward speed km/h × nozzle spacing cm) ÷ 60000. The constant 60000 converts the mix of units (litres, km/h, cm, hectares) into a clean per-minute flow. The calculator does this for you and also shows the result in US gallons per minute so you can match a nozzle catalogue in either unit.
Why does each nozzle need a specific flow?+
A boom sprayer applies the target spray volume per hectare by having every nozzle deliver a set flow at the chosen speed and spacing. If the flow is too high you over-apply and waste chemical; too low and you under-dose, risking poor control or resistance. Calculating the required flow lets you choose a nozzle and pressure that hit the target accurately and evenly across the boom.
What inputs do I need?+
Three things: the target spray volume per hectare (L/ha) from the product label or your agronomy plan, your forward speed in km/h, and the nozzle spacing along the boom in cm (commonly 50 cm). The calculator combines them into the required output per nozzle, plus the resulting spray volume per hectare and the speed, so you can confirm the setup.
How do I measure forward speed accurately?+
Mark a measured distance in the field, drive it in the working gear and throttle you'll spray at — with a part-full tank for realistic weight — and time it. Speed (km/h) = distance (m) ÷ time (s) × 3.6. Use this real measured speed, not the speedometer, because tyre slip and terrain change ground speed and therefore the flow each nozzle needs.
Which pressure should I run?+
Once you know the required flow per nozzle, pick a nozzle whose chart delivers that flow within its recommended pressure band — typically 1.5–4 bar for flat-fan nozzles. Staying in band keeps droplet size and pattern correct: too low and the fan collapses, too high and you make fine, drift-prone droplets. Adjust pressure only within the nozzle's range to fine-tune output.
What is nozzle spacing and why does it matter?+
Nozzle spacing is the distance between nozzles along the boom, usually 50 cm. It sets how much ground each nozzle covers, which directly affects the flow each must deliver for a given per-hectare volume. Wider spacing means each nozzle covers more ground and needs more flow; the calculator accounts for your actual spacing so the per-nozzle output is right.
Should I still do a physical calibration?+
Yes — this calculator gives you the target flow to select nozzles and a starting pressure, but always confirm with a real calibration: catch the output from several nozzles for a timed minute and check they match the target and each other. Worn nozzles over-deliver and uneven nozzles cause streaking, so physical checks remain essential. Use the Sprayer Calibration tool for the full procedure.
Does it work for different volumes and crops?+
Yes — enter any target spray volume per hectare and the calculator returns the required nozzle flow for that rate, whether you're applying a low-volume herbicide or a high-volume fungicide. Just match the volume, speed and spacing to your job, and reselect nozzles when you change to a very different application rate or crop canopy.
Are the figures exact?+
The formula is exact for the inputs you give, but real application depends on accurate speed measurement, correct pressure, and nozzle condition and wear. Treat the output as the precise target to select and set nozzles, then verify by catching real output and checking coverage — good spraying combines the right calculation with a physical calibration.