Drip Irrigation Calculator & Flow Rate & Run Time
Designs drip for orchards
Design a drip run in seconds — from plot, spacing and emitter discharge get the plant and emitter count, the system flow rate, daily water, and the run time to meet your crop's need.
At this spacing the plot holds about 5,620 plants on 5,620 emitters, drawing 22 m³/h (6.24 lps) when running. To give each plant its 4.32 L/day, run the system about 1 h 5 min.
Next: size your pump and mainline to at least the system flow, and split into shifts (zones) if your source can't deliver it all at once. Check emitter discharge against pressure, and flush lines regularly.
A planning estimate — actual need varies with crop stage, soil and weather, and emitter output depends on operating pressure.
Drip irrigation — key facts
- Run time
- need ÷ emitter flow/plant
- System flow
- emitters × discharge
- 1000 lph
- = 1 m³/h ≈ 0.28 lps
- Common emitters
- 2 / 4 / 8 lph
- Drip efficiency
- ≈ 90%
- 1 mm/m²
- = 1 litre
- Frequency
- daily / alternate days
- Privacy
- Runs in your browser; nothing uploaded
How the drip design is worked out
Plant and row spacing set how many plants fit the plot, and emitters per plant set the emitter count and the flow each plant receives. Multiply all emitters by their discharge for the system flow rate — the figure that sizes your pump, mainline and number of zones. For scheduling, the tool takes each plant's daily water need (entered directly, or from crop ET spread over the plant's ground area) and divides by the per-plant flow to give the run time per irrigation.
Drip's advantage is precision: water goes straight to the root zone at about 90% efficiency, so getting the run time right avoids both stress and wasteful deep percolation. Because the wetted volume is small, drip is run little and often. Use the flow figure to confirm your source can supply the whole field at once — if not, split it into zones and irrigate in shifts.
Schedule irrigation
Get the daily run time to deliver exactly the water your crop needs — no stress, no waste.
Size pump & pipe
Use the system flow rate in lps and m³/h to choose a pump and mainline that can keep up.
Plan zones
If flow demand exceeds your source, see that you need to split the field into irrigation shifts.
Compare methods
Pair with the Irrigation Water Calculator to see drip's water saving versus flood and sprinkler.
Frequently Asked Questions
How do I calculate drip irrigation run time?+
Divide each plant's daily water need (litres) by the water its emitters deliver per hour. If a plant needs 4 litres a day and has one 4 lph emitter, run time is 1 hour. With two 4 lph emitters (8 lph) it halves to 30 minutes. This tool computes it from your layout and crop need.
How do I find my system flow rate?+
Multiply the total number of emitters by each emitter's discharge. A plot with 1000 plants and one 4 lph emitter each draws 4000 lph — that's about 1.1 litres per second or 4 m³ per hour. The tool shows all three units so you can size pumps and pipes.
How many emitters does each plant need?+
Widely spaced crops (trees, vegetables) often use one or two emitters per plant; closely spaced row crops use inline drip line where emitters are spaced along the lateral. Set emitters per plant to match your design and the tool scales the flow and run time accordingly.
What is emitter discharge?+
Emitter discharge is the flow rate of a single dripper, usually 2, 4 or 8 litres per hour at the rated pressure. Pressure-compensating emitters hold that rate over a range of pressures, which keeps application even along long laterals and on slopes.
How do I know my crop's daily water need?+
You can enter it directly as litres per plant per day, or switch to ET mode and give the crop's evapotranspiration in mm/day — the tool multiplies it by each plant's ground area (plant spacing × row spacing) to get litres. Crop water need rises with temperature, wind and crop stage.
Why split irrigation into zones?+
If your whole field's flow demand exceeds what your source or pump can deliver at once, you divide it into zones (shifts) and irrigate them one after another. Knowing the system flow rate tells you whether you need zones and how many.
Does drip save water versus flood irrigation?+
Yes — drip delivers water directly to the root zone at high efficiency (around 90%), versus roughly 60% for flood, so it can cut water use substantially while improving yields and allowing fertigation. Our Irrigation Water Calculator compares methods in detail.
What pump size do I need for drip?+
Your pump must supply at least the system flow rate (or the largest zone's flow) at the pressure the emitters need. Add friction losses in the mainline and laterals and the lift from your water source; size the pump above the peak demand with a margin.
How often should I run drip irrigation?+
Most drip systems run daily or every other day in short sessions, because the small wetted volume holds little reserve. The tool gives the run time to replace one day's use; on very sandy soils split it into two shorter runs to reduce deep percolation.
How accurate is this design estimate?+
It's a sound planning estimate from your inputs. Real performance depends on operating pressure, emitter clogging, slope and how evenly the system is laid out, so calibrate by checking emitter output in the field and adjust run time to your soil and weather.