Calculate the total water volume needed to irrigate your field to a given depth, and how long it will take with your pump's discharge rate.
How to Use the Irrigation Calculator
Enter your "Land Area (acres)".
Enter the "Irrigation Depth (mm)" you want to apply - typically 50-75mm per watering, depending on crop and soil type.
Optionally enter your "Pump Discharge Rate (liters/hour)" to estimate how long irrigation will take.
Click "Calculate Water Required" to see the total water volume and irrigation time.
Frequently Asked Questions
Conveniently, applying 1mm of water depth over 1 square meter equals exactly 1 liter. So the total water volume (liters) = Area (m²) × Depth (mm), where the area is first converted from acres to square meters.
This varies by crop, growth stage, soil type, and climate. Many field crops are irrigated with 40-75mm per watering - check your crop's specific water requirement guidelines or your local agriculture extension office for precise figures.
No, this calculates the theoretical water volume delivered to the field. Actual pumped water needed will be higher due to conveyance and application losses, especially with flood irrigation versus drip or sprinkler systems.
Yes, it's completely free and requires no sign-up.