Gardening
Irrigation Flow Calculator
Enter pipe flow (L/min) or emitters × L/h, plus a target volume, to see total flow and run time.
How long should an irrigation zone run?
Irrigation zones are sized by flow: either a pipe rating in litres per minute or a set of emitters each delivering litres per hour. Convert emitters × L/h into L/min (divide by 60), then divide a target volume by that flow to get run time. A bed that needs 40 L with 20 emitters at 2 L/h is about 0.67 L/min and roughly 60 minutes. Pressure, elevation and dirty filters change real output — treat the result as a timer starting point. Weekly water totals pair with drip irrigation; plant counts link to garden bed planner.
Worked example
20 emitters × 2 L/h = 40 L/h ≈ 0.67 L/min. For 40 L target → about 60 minutes.
Limits and assumptions
Steady rated flow. Does not model pressure compensation curves or overlapping spray patterns.
Frequently asked questions
What is L/h vs L/min?
Litres per hour is common on drip emitters; litres per minute is common on hose and pipe ratings. Divide L/h by 60 to get L/min.
Pipe mode or emitters?
Use emitters when you know count and drip rating; use pipe mode when a meter or pump quotes L/min.
Target volume — how do I pick it?
From soil type and crop need, or from a weekly litre budget split across sessions.
Can I run multiple zones?
Calculate each zone separately — flows do not simply add if they share a undersized main.