Sprinkler Runtime by Lawn Size (How Much and How Long?)

Updated 2025-09-04

A common target for cool-season lawns is about 1 inch of water per week (check local guidance). If your sprinkler system applies water at R inches per hour (precipitation rate), the runtime to deliver 1 inch is roughly 1 ÷ R hours. For example, at 0.5 in/hr, you need ~2 hours total per week, often split into 2–3 sessions to minimize runoff.

Quick Runtime Estimator

  • 0.4 in/hr → ~2.5 hours/week
  • 0.5 in/hr → ~2.0 hours/week
  • 0.75 in/hr → ~1.3 hours/week

To quantify water volume and cost, use the Sprinkler Calculator with your flow rate and schedule. For related indoor savings, see our Shower Flow Rate Chart and Dripping Faucet guides.

Best Practices

  • Water early morning to reduce evaporation.
  • Use cycle-and-soak for heavy soils to prevent runoff.
  • Adjust for rainfall—use a rain sensor or smart controller.
Open Sprinkler Calculator