Sprinkler Irrigation Time Calculator
Calculate sprinkler precipitation rate and the run time to apply a target water depth.
Precipitation rate (mm/h) is sprinkler discharge per hour divided by the area each sprinkler covers (spacing × lateral spacing). Keep the precipitation rate below the soil's infiltration rate to avoid runoff.
Indicative planning figures based on published research averages. Local soil tests, varieties and weather change actual requirements — confirm with your agronomist or extension officer.
Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates — verify with a qualified professional before making decisions. Read the full disclaimer.
Farmers and irrigation engineers use the free Sprinkler Irrigation Time Calculator to get an accurate answer in seconds — no formulas to remember, works offline in the field.
About Sprinkler Irrigation Time Calculator
A sprinkler's precipitation rate — how fast it lays down water in mm/h — depends on its discharge and the grid spacing it sits in. Get it wrong and you either under-irrigate or, worse, exceed the soil's infiltration rate and lose water to runoff. This tool computes the precipitation rate from your sprinkler discharge and spacing, then tells you how long to run the set to apply a target depth.
How to use Sprinkler Irrigation Time Calculator
- 1Enter your system or field values into the inputs.
- 2Read the headline result and the supporting breakdown.
- 3Apply the guidance in the note to your irrigation plan.
Why use Sprinkler Irrigation Time Calculator?
- ✓Uses the standard, citable irrigation engineering formula
- ✓Clear inputs with sensible defaults
- ✓Instant result with the working shown
- ✓Free, fully in-browser and private
Frequently asked questions
How is sprinkler precipitation rate calculated?+
Multiply the sprinkler discharge (L/min) by 60 to get L/h, then divide by the area it covers (sprinkler spacing × lateral spacing in m²). The result is the precipitation rate in mm/h. Run time is your target depth divided by this rate.
Why must precipitation rate stay below infiltration rate?+
If sprinklers apply water faster than the soil can absorb it, the excess ponds and runs off — wasting water and causing erosion. Choose nozzle size and spacing so the precipitation rate is below your soil's infiltration rate (e.g. <8 mm/h on heavy clay).
Is this tool free and private?+
Yes — free, no sign-up, and all calculation runs in your browser, so it works offline and your data never leaves the device.
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