Irrigation Water Requirement Calculator
How long should the tube-well run? Enter the area, the depth of water you want to apply and the discharge of your tube-well or outlet.
Updated
Results are estimates for planning. Actual figures depend on local conditions, prices and quotes — verify before making decisions.
Formula
Volume (m³) = Area (acres) × Depth (inches) × 102.79
Hours = Volume ÷ (Discharge in cusec × 101.94)
1 acre-inch is 102.79 m³ of water. A 1-cusec flow delivers 101.94 m³ per hour — so 1 cusec applies roughly 1 acre-inch per hour.
Examples
1 acre, 3 inches, 1 cusec
1 acre at 3 inches needs 308 m³ of water — about 3 h 1 min at 1 cusec
5 acres, 4 inches, 0.75 cusec
5 acre at 4 inches needs 2,056 m³ of water — about 26 h 53 min at 0.75 cusec
Important information
- Real application takes longer because of conveyance and field losses. Laser land levelling can cut water use substantially.
- Crop water needs vary with season and growth stage — follow local irrigation schedules.
Frequently asked questions
What is a cusec?
One cubic foot per second — about 28.3 litres per second.
How many inches of water per irrigation?
Commonly 3–4 inches for most crops; the first irrigation after sowing or for dry soil may need more.
What is an acre-inch?
The volume of water that covers one acre to a depth of one inch — about 102,790 litres.
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