Irrigation Cost Calculator
Work out the electricity or diesel cost of pumping irrigation water, per irrigation and for the season.
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How much does it cost to run your pump? Choose an electric motor or diesel engine, enter the hours and your tariff or fuel price, and see the cost per irrigation, for the season and per acre.
About the Irrigation Cost Calculator
Pumping water is a hidden cost on many farms, especially with diesel engines or where farm electricity is metered. Knowing the cost per irrigation helps you compare flood irrigation with sprinkler or drip, decide whether a solar pump makes sense, and set a realistic cost of cultivation.
Electric motors are rated in horsepower (HP) or kilowatts (kW). One HP is 0.746 kW, and one kWh is the "unit" on your electricity bill. A 5 HP motor running for one hour uses roughly 3.7 units – often a little more, because motors draw more than their rated output when they are old, rewound or poorly matched to the pump.
Diesel engines are easiest to cost from fuel use per hour. Fill the tank to the brim, run for a measured time, and see how much you need to top up.
How to use the Irrigation Cost Calculator
- 1 Choose electric motor or diesel engine.
- 2 For electric, enter the motor rating (HP or kW) and your rate per unit. For diesel, enter litres per hour and the diesel price.
- 3 Enter how many hours you pump per irrigation and how many irrigations you expect.
- 4 Add labour and your area if you want, then press Calculate cost.
The formula we use
Electric: Units (kWh) = Motor kW × Hours × Irrigations
Energy cost = Units × Rate per unit
Diesel: Diesel (L) = Litres per hour × Hours × Irrigations
Energy cost = Diesel × Price per litre
Total = Energy cost + Labour × Irrigations1 HP = 0.7457 kW.
Worked example
A 5 HP electric motor runs 6 hours per irrigation for 5 irrigations, at ₹5 per unit, with ₹200 labour per irrigation.
- Motor power = 5 × 0.7457 = 3.73 kW.
- Units = 3.73 × 6 × 5 = 111.9 kWh.
- Electricity = 111.9 × ₹5 = ₹559.
- Labour = ₹200 × 5 = ₹1,000.
- Total = ₹1,559, or about ₹312 per irrigation.
Things to keep in mind
- Rated vs actual power. Motors usually draw somewhat more than rated power. If you have a meter, the actual units used is the best figure.
- Fixed charges. Some farm connections have fixed monthly or HP-based charges. Add them as labour/other cost if you want the full picture.
- Efficiency pays. Leaking pipes, foot valves and undersized suction pipes increase pumping hours. So does over-irrigating.
Frequently asked questions
How many units does a 5 HP motor use per hour?
A 5 HP motor is 3.73 kW, so about 3.7 units per hour at full load. In practice it is often 4–4.5 units because of motor and pump losses.
How much diesel does a 5 HP engine use per hour?
Commonly around 0.8–1.2 litres per hour depending on load and engine condition. Measure yours by topping up after a timed run.
How can I reduce irrigation cost?
Irrigate based on crop need, fix leaks, use a correctly sized pump, and consider drip or sprinkler systems. Solar pumps remove fuel and power costs after the initial investment.
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