Irrigation Timer Calculator — Watering Duration & Frequency

Run time depends on how fast your system applies water (its precipitation rate), not on the area watered — a sprinkler lays down the same depth per hour whether the lawn is small or large. A typical garden oscillating sprinkler applies about 12.5 mm per hour (10-15 mm). For a 25 mm weekly need spread over 3 sessions, that is roughly 8 mm per session, so about 40 minutes per session (around 2 hours per week in total).

Early morning (6-8 AM) is ideal. Less evaporation, leaves dry before evening (reducing disease), and water pressure is usually higher.

In summer, most gardens need 20-25mm per week. In spring/autumn, 10-15mm. Reduce by rainfall received.

Yes. Drip irrigation delivers water directly to roots with minimal evaporation. It uses 30-50% less water than sprinklers.

Morning is best. Plants take up water during the day and leaves dry quickly, reducing disease risk. Evening watering is the second choice but can promote slug activity and fungal problems.