Lawn Irrigation Calibrator

Place one or more catch cups (e.g. empty tin cans) in the spray area, run your sprinkler for a set time, and measure the collected water. This calculator turns that into your sprinkler's precipitation rate and the run time needed to reach your target weekly amount.

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Run time per week

Pro tips

Best to place several cups around the area and use the average reading.
Watering early in the morning reduces evaporation and fungal risk.

All calculations are non-binding estimates provided without guarantee. For safety-relevant decisions (e.g. pool chemistry), please consult a professional.

Frequently Asked Questions

How do I properly calibrate my sprinkler?

Place a flat container in the spray zone, measure the water collected after a set time, and scale it up to a per-hour precipitation rate.

How much water does lawn need per week?

A general guideline is 2.5-4 cm of water per week, depending on weather, soil type and grass variety.

How long should I run the sprinkler?

It depends on your sprinkler's precipitation rate – the calculator above works out the right run time for your target water amount from your calibration test.

Is it better to water in the morning or evening?

Early morning is best, since the water can soak in deeply before the sun evaporates it, and the blades dry off by evening (lower risk of fungus).