Pump Run Time & How Long to Irrigate?
Times the run
Enter the water you need and your pump's flow to get the run time in hours and minutes, the water required in m³, the pump flow in m³/h and the energy used.
Enter your irrigation
Next: run about 2.78 h to deliver 100 m³; split into sets on slow-infiltration soils to avoid runoff.
Assumes steady pump output; real flow falls as the water table drops or filters clog — measure your actual delivery.
Pump run time — key facts
- Run time
- water needed ÷ pump delivery
- Required volume
- depth (mm) × area (m²) ÷ 1000
- Pump flow
- L/s × 3.6 = m³/h
- Energy
- motor kW × hours = kWh
- 1 mm over 1 ha
- = 10 m³ (10,000 L)
- Slow soils
- split into sets to avoid runoff
- Use
- schedule power or diesel precisely
- Privacy
- Runs in your browser; nothing uploaded
Run the pump to a number, not a guess
Most field watering is timed by habit — switch on, come back later, hope it was about right. But the answer is simple arithmetic: divide the water the field needs by how much the pump delivers each hour and you have the exact run time. Work the water need from depth and area, convert a litres-per-second rating to cubic metres an hour, and you can set a timer with confidence. That stops both the waste of over-watering and the stress of under-watering.
This tool gives the run time in hours and minutes, the water required in m³, the pump flow in m³/h and the energy used, so you can schedule a power slot or plan a diesel run to the litre. On slow-infiltration soils, split the total into sets to avoid runoff. Pair it with the Pump Efficiency, Irrigation Scheduling and Irrigation Water tools to run a tight, low-cost system.
Stop guessing the timer
An exact run time from water needed and flow.
Avoid over-watering
No wasted water, leaching or extra power cost.
Budget the energy
kWh per run feeds your electricity or diesel bill.
Split for slow soils
Divide the run into sets to stop runoff.
Frequently Asked Questions
How is pump run time calculated?+
Run time = water needed ÷ pump delivery. If you need 60 m³ of water and your pump delivers 30 m³ per hour, you run it for 2 hours. The tool does this for you and splits the answer into hours and minutes so you can set a timer or plan the irrigation slot.
How do I work out the water I need?+
Either enter the required volume directly in m³, or let the tool compute it from depth and area: required volume (m³) = depth (mm) × area (m²) ÷ 1000. So a 25 mm application over a 4,000 m² plot needs 25 × 4000 ÷ 1000 = 100 m³ of water.
How do I convert my pump flow to m³/h?+
If your pump is rated in litres per second, multiply by 3.6 to get cubic metres per hour: pump flow (m³/h) = L/s × 3.6. A 10 L/s pump therefore delivers 36 m³/h. Enter the flow in whichever unit you have and the tool handles the conversion.
Why does knowing run time matter?+
Knowing the run time prevents over- and under-irrigation. Run too long and you waste water, leach nutrients and run up the power or diesel bill; run too short and the crop is stressed. A calculated time lets you schedule the power slot or fuel run precisely instead of guessing.
How much energy will the run use?+
Optionally enter the motor power in kW and the tool estimates energy = motor kW × hours. A 5 kW pump run for 2 hours uses about 10 kWh. That figure feeds straight into your electricity or diesel cost so you can budget each irrigation.
Should I run the pump in one go or in sets?+
On slow-infiltration soils, applying all the water at once causes ponding and runoff. Split the run into sets — for example two shorter runs with a gap — so the soil can soak it in. The tool's run time is the total; divide it across the number of sets you choose.
What if my field is in acres or hectares?+
Convert area to square metres first: 1 acre ≈ 4,047 m² and 1 hectare = 10,000 m². Then the depth-times-area formula gives the volume in m³. Many farmers keep area in m² in the tool so the water volume comes out directly without extra conversion.
Does pumping head affect run time?+
Head affects the pump's actual delivery, not the formula. A pump pushing against high lift delivers fewer m³/h than its rated figure, so use the real measured flow at your conditions for an accurate run time. Check delivery with a bucket-and-stopwatch test if unsure.
Can I use this for filling a tank?+
Yes — enter the tank volume in m³ as the water required and your pump flow, and the run time tells you how long to fill it. It works for any fill-a-volume task: ponds, storage tanks, troughs or a section of field.
Are the results exact?+
They're a practical estimate. Real delivery varies with head, wear, pipe friction and voltage, and infiltration losses mean some applied water never reaches the root zone. Treat the run time as a starting schedule and fine-tune by checking soil moisture after a few cycles.