A method to convert daytime evapotranspiration (ET) into daily ET based on variable canopy resistance was investigated in this paper. The study was carried out for maize and canola crops grown in Coleambally Irrigation Area which is located in Murray Darling Basin of Australia. Variable canopy resistance was simulated on the basis of Todorovic method. This study has shown that the method performed well to scale daily ET from daytime ET measurements for both crops. In the case of the maize crop, the coefficient of determination (R2) was 0.979 and the index of agreement (d) was 0.981. In the case of the canola crop, the coefficient of determination (R2) was 0.936 and the index of agreement (d) was 0.960. Future work will focus on the study of this method to scale daily ET map from satellite-derived daytime ET map.