How long should I run my sprinkler?
Quick answer
Long enough to apply the amount of water you're aiming for, which depends on how fast your sprinkler puts water out. Find out with a catch-cup test: run the zone for a set time, measure the water in straight-sided cups, and work out the minutes needed. Then follow your local water rules for days and times.
Why this happens
Two sprinklers running for the same 20 minutes can apply very different amounts of water. Pop-up sprays, rotors and hose-end sprinklers all put out water at different rates, and pressure and spacing change it again. That’s why run time should come from a measurement, not a guess.
The measurement is a catch-cup test. Spread straight-sided containers across the zone (tuna cans or straight-sided cups work), run the zone for a fixed time and measure how many millimetres landed in each. From the average you can work out:
- the application rate in millimetres per hour
- the run time needed to apply your target, such as 10 mm
- how evenly the zone waters, from the gap between the lowest cups and the average
The Sprinkler Run-Time Calculator does all three from your readings.
If coverage is uneven
If some cups collect much less than others, the zone has dry spots. Running it longer drowns the wet areas to get enough onto the dry ones. Fix the cause instead: blocked or tilted heads, mismatched nozzles, low pressure or heads too far apart. Then re-test.
Run-off and soil type
Many systems apply water faster than clay or compacted soil can absorb it. If water runs off before the run time is up, split it into two or three shorter cycles with a break between them. Sandy soil soaks it up quickly but may be water-repellent when dry, which a wetting agent helps with.
Check the rules
Your water authority decides which days and times sprinklers can run. Set your controller within those rules, and adjust run times with the season.
What you can do
Set out cupsCheck first
Place at least six straight-sided containers across one zone, away from the sprinkler heads and evenly spread.
Run the zoneCheck first
Run it for a set time (for example 15 minutes) on an allowed watering day and time.
Measure each cupCheck first
Use a ruler to measure the depth of water in millimetres.
Use the calculator
Enter the readings in the Sprinkler Run-Time Calculator to get the run time for your target and see how evenly the zone waters.
Fix uneven coverage first
If some cups have much less, adjust or replace heads before increasing run time.
Split long runs
If water starts running off before the time is up, split it into two shorter cycles so it can soak in.
What not to do
- Copying someone else's run time; every system puts out water at a different rate.
- Making up for one dry spot by running the whole zone longer.
How much do I need?
Place straight-sided containers around the zone, run it for a set time, then measure the depth of water in each with a ruler. How to do a catch-cup test
Run time for this zone
Enter at least two cup readings, the test time and the water you want to apply.
Log it
Keep a record of what you applied, when, and at what rate. Your Lawn Journal works on this device without an account, and reminds you when the next step is due.
What's next
Related questions
Related guides
- Irrigation guideThe catch-cup test: measure what your sprinklers actually put out
- Irrigation guideHow much water does a lawn need?
- Irrigation guideChoosing sprinklers: pop-ups, rotors, oscillating and hose-end
- Irrigation guideSmart irrigation controllers and rain sensors: how to choose and set them up
- Application guideApplying liquid fertiliser
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Sources
- How long should I run my sprinklers for?, Water Corporation (Western Australia)Catch-cup test to set run times and check distribution. Accessed 4 October 2026.
- How much water does my garden need?, Water Corporation (Western Australia)How much water lawns need in summer (Perth and South West). Accessed 4 October 2026.