Evapotranspiration Calculator
Estimate crop evapotranspiration (ETc) using reference ET (ETo) and crop coefficient (Kc).
Inputs
How It Works
Crop ET (ETc) = Reference ET (ETo) × Crop Coefficient (Kc)
Weekly ET = Daily ET × 7
Kc varies by crop type and growth stage.
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FAQ
What is evapotranspiration?
Evapotranspiration is the combined water loss from soil evaporation and plant transpiration.
What is reference ET (ETo)?
Reference ET represents water loss from a standardized grass surface under current weather conditions.
What is crop coefficient (Kc)?
Crop coefficient adjusts reference ET to match specific crop water use and growth stage.
Understanding Evapotranspiration in Irrigation Management
Evapotranspiration (ET) is a critical measurement in irrigation management and crop water planning. It represents the total amount of water lost through soil evaporation and plant transpiration. Accurate ET calculations help producers determine how much water crops actually use and guide irrigation scheduling decisions.
Reference evapotranspiration (ETo) is calculated from weather data including temperature, humidity, wind speed, and solar radiation. The crop coefficient (Kc) adjusts ETo to reflect specific crop water use at various growth stages. Multiplying ETo by Kc provides crop evapotranspiration (ETc), which estimates daily crop water demand.
Using an evapotranspiration calculator allows farmers to improve irrigation efficiency, conserve water, and maintain optimal soil moisture levels. When combined with irrigation scheduling and water application depth calculations, ET management supports sustainable and profitable crop production.