Over-irrigation wastes water and can leach nutrients or promote root disease, while under-irrigation stresses crops during critical growth stages. This calculator converts your field area and target water depth into the actual volume of water needed and the pumping time and cost required to deliver it, factoring in your system's real-world efficiency.
Water Volume (liters) = Field Area (converted to m²) × Water Depth (mm) ÷ System Efficiency. Pumping Time = Water Volume ÷ Pump Flow Rate. Water Cost = (Water Volume ÷ 1000) × Cost per 1000 Liters (where applicable, e.g., for purchased or metered water).
| Irrigation Method | Typical Efficiency |
|---|---|
| Flood/furrow | 40-55% |
| Sprinkler | 70-80% |
| Drip | 85-95% |
For 2 hectares (20,000 m²) needing 50 mm of water via flood irrigation at 50% efficiency: Water volume = 20,000 × 50 ÷ 0.5 = 2,000,000 liters. At a pump flow rate of 2,000 liters/minute, pumping time = 2,000,000 ÷ 2,000 = 1,000 minutes (≈16.7 hours). Switching the same field to drip irrigation at 90% efficiency would cut required volume to about 1.11 million liters — roughly 44% less water for the same crop benefit.
Flood irrigation loses a large share of applied water to deep percolation beyond the root zone and surface runoff, while drip irrigation delivers water directly to the root zone with minimal loss — this is why efficiency percentages differ so widely between methods.
This depends on crop type, growth stage, and local evapotranspiration rates, which our Crop Water Requirement Calculator estimates in more detail. As a general guide, most field crops need 400-600mm total water depth across a full season, split across multiple irrigation events.
Water savings are consistent, but the upfront investment in drip infrastructure needs to be weighed against those savings — our Drip Irrigation Cost Calculator estimates that investment so you can compare it against the water and, often, yield gains over time.
Yes — run the calculation separately for each field using its specific method and efficiency, then add the results together, since mixing methods in a single calculation would give you a less accurate average efficiency.