🚿 Sprinkler Coverage Calculator

Are Your Sprinklers Actually Working? The Catch Can Test

Most homeowners set their sprinkler timers based on minutes, not volume. However, different sprinkler heads (rotary vs. fixed spray) deliver water at vastly different rates. The only way to know exactly how much water your lawn is receiving is to perform a Catch Can Test.

How to Conduct a Catch Can Test

You don't need expensive equipment. You can use empty tuna cans or specific irrigation catch cans:

1. Place 5-10 cans randomly throughout one watering zone.
2. Run that zone for exactly 15 minutes.
3. Measure the depth of water in each can with a ruler and find the average.
4. Multiply by 4 to get your Precipitation Rate in inches per hour.

Understanding Precipitation Rates

If your catch can average is 0.25 inches in 15 minutes, your rate is 1 inch per hour. If your lawn needs 1.5 inches of water per week, you need 90 minutes of total run time. Our calculator does this math for you instantly, helping you avoid dry spots and wasted water.