The population growth and climatic factors negatively impact the current scenario of reduced water availability. In particular, agriculture has become one of the most severely affected economic areas since it uses a significant amount of freshwater. Therefore, it has become necessary to implement strategies to accurately determine water demand at the field level to optimize water use. To achieve this, new digital agriculture techniques based on the use of remote sensing have made it possible to obtain spatially distributed information that, in combination with biomathematical modeling, would allow the spatial and temporal determination of the water consumption of crops. Therefore, this research proposes the development of a Web Platform (Millimetric) capable of processing and interacting with maps based on geospatial information and meteorological data to determine the crop water consumption based on the original formulation of the METRIC model. In a complementary way, Black box and usability tests were carried out on users to validate the usability of the system. The results showed that the platform allowed to obtain information consistent with the literature. However, the errors in the estimates indicated the need to carry out calibrations and validations of the METRIC sub-models associated with the land's topography, crop type, and meteorology of the place to obtain more precise results. Finally, regarding usability, users reported that the front-end configuration allowed a simple and effective use of the information.