Tool

Sprayer Calibration Calculator

Find out how much water your sprayer and walking pace actually put out, so you can match the water volume on a product label.

  1. Mark out a test area on the lawn, at least 10 m².
  2. Fill the sprayer with a measured amount of clean water.
  3. Spray the test area at your normal pace and pressure.
  4. Measure how much water is left, and work out how much you used.
m²
L
L / 100 m²
As litres per 100 m². If the label gives litres per hectare, divide by 100.

Your sprayer's output

Enter your test area and the water you used.

How it works

A label might say “apply in 5 L of water per 100 m²”. Whether you actually do that depends on your nozzle, pump pressure and walking speed. Calibrating with clean water shows you what your sprayer really puts out, so the product goes on at the rate the label intends.

Worked example

Mark out 10 m² (for example 5 m × 2 m) on the lawn. Fill the sprayer with clean water, spray the area at your normal walking pace, then measure what you used: 0.6 L. That's 6 L per 100 m². If the label asks for 5 L per 100 m², you are putting out 20% too much: walk a little faster or use a lower-output nozzle, then test again.

What you enter

  • Test area in m²
  • Water used in litres
  • Optional water volume from the label (L per 100 m²)

What you get

  • Your output in litres per 100 m²
  • How it compares with the label water volume

Assumptions

  • Calibrate with clean water only.
  • Keep the same nozzle, pressure and walking pace you will use on the day.

Questions

How big should my test area be?

At least 10 m². Larger areas give more reliable results because small measuring errors matter less.

How often should I calibrate?

Before first use, whenever you change nozzles or sprayers, and at the start of each season.