Guide
How long should I water my lawn?
A lawn needs about an inch of water a week, rain included. How long that takes depends on your sprinkler.
The calculation
- Water per week: about 1 inch is a common target, rain included.
- Your sprinkler's rate, in inches per hour.
- Minutes per week = water per week ÷ rate × 60, then split into your waterings.
Example
A sprinkler that puts down 0.5 inch per hour needs 2 hours for 1 inch. Watering twice a week: 60 minutes each time.
The can test
Do not know your sprinkler's rate? Set a few straight-sided cans on the lawn, run the sprinkler for 15 minutes, and measure the water in each. The average depth times 4 is the rate in inches per hour.
From the flow
If you know the flow in gallons per minute and the area it waters, the rate in inches per hour is the flow × 96.25 ÷ the area in square feet. Time how long the sprinkler takes to fill a bucket of known size to find the flow.
With Lawn Calc
Enter the sprinkler once, choose the water per week and how many times you water, and each zone shows its minutes. See Watering.
