Crop Water Requirement Calculator
Enter your own ETo, Kc, area, and efficiency values. The tool applies ET₀ × Kc × area ÷ efficiency and reports the resulting water volume in your chosen units.
Enter all four values to calculate local water volume.
Assumes ETo in mm/day, area in m², and efficiency as a decimal. Enter Kc from your agronomic source.
A QUICK WALKTHROUGH
How to use this tool
- Enter ETo and Kc from your agronomic source.
- Enter area and irrigation efficiency as a decimal fraction.
- Calculate and review the formula, assumptions, and output.
Transparent formula
Daily water volume = ET₀ × Kc × area ÷ irrigation efficiency. Enter efficiency as a decimal fraction such as 0.75, not 75.
You provide agronomic inputs
The calculator does not invent crop coefficients, ETo values, weather data, soil assumptions, or irrigation recommendations. Use values appropriate to your crop, location, and growth stage from a trusted source.
Unit assumptions
ETo must be in millimetres per day and area in square metres for litres per day. Other units are converted with explicit factors shown in the form; this is a planning calculation, not agronomic advice.
GOOD TO KNOW
Common questions
Does it provide a crop coefficient?
No. Enter Kc from your own agronomic source.
How should I enter efficiency?
Use a decimal from greater than 0 to 1, such as 0.75 for 75%.
Is this irrigation advice?
No. It is a transparent calculation whose result depends on your inputs and unit assumptions.