๐ง Drip Irrigation Calculator
Enter your growing area dimensions and emitter specs to get total emitter count, system flow rate and daily water usage โ so you can size your pump, filter and irrigation zones. All calculations run locally in your browser.
โ
Daily water usage
โ
Emitters per line
โ
Total emitters
โ
System flow rate
โ
Suggested irrigation zones
๐ก Tip: operate drip systems at 8-25 PSI. For surface drip tape, always install a 120-mesh filter to prevent clogging.
๐งฎ How It Works
Drip system design aims for even emitter flow and keeps total flow within the mainline and pump capacity:
Emitters per line = โ length ร 12 / emitter spacing โ (imperial)
Total emitters = emitters per line ร number of lines
System flow rate = total emitters ร flow per emitter
Daily water usage = system flow rate ร run hours per day
Suggested zones = โ system flow / 12 GPM โ (3/4-inch mainline limit)
๐ Drip Irrigation Reference
| Parameter | Typical value | Notes |
|---|---|---|
| Emitter flow | 0.5 / 1 / 2 GPH (2/4/8 L/h) | Sandy soil: higher flow; clay soil: lower flow |
| Emitter spacing | 12 in (30 cm) | Tighten to 8 in on sandy soil, relax to 18 in on clay |
| Operating pressure | 8-25 PSI (0.55-1.7 bar) | Too high bursts lines, too low gives uneven flow |
| Mainline safe flow | โค 12 GPM (45 L/min) | 3/4-inch PE pipe; above this, zone or use 1-inch |
| Filter mesh | 120 mesh (โ130 micron) | Mandatory for well/river water |
| Per-emitter daily delivery | 0.5-1 gal (2-4 L) | Adjust run time for crop and season |
โ FAQ
How much water does a 1 GPH emitter deliver per day?
A 1 GPH emitter delivers 1 US gallon (about 3.78 L) per hour. Run 30 minutes a day and it delivers about 0.5 gallons (1.9 L); run 1 hour and it delivers about 1 gallon. Vegetable beds typically run 20-40 minutes per day, adjusted for soil and crop needs.
How do I choose an emitter flow rate? Sandy vs clay soil?
Sandy soil drains fast and spreads water poorly sideways, so use 2 GPH (8 L/h) fast emitters with tighter spacing. Clay soil drains slowly and spreads well, so 0.5-1 GPH (2-4 L/h) slow emitters work better and avoid waterlogging. For standard vegetable beds, use 1 GPH (4 L/h) emitters at 12-inch spacing.
How many emitters can one mainline supply?
A 3/4-inch PE mainline is safely rated around 12 GPM (about 45 L/min). Above 12 GPM, split the system into zones or upgrade to a 1-inch mainline. This calculator suggests the number of zones you need so you can plan valves and rotation.
Do I really need a filter on a drip system?
Yes. Drip emitter paths are very narrow (0.6-1.2 mm) and clog easily. For well or river water, install a 120-mesh disc or screen filter. Even on city water, use at least a 60-80 mesh filter and add an end flush valve to rinse the lines regularly.