A method for assessing the amount of content stored within a container, such as a farm silo, having a given shape defined by a 3D model on a given reference system and storing a given amount of content, said method comprising: - attaching, on a top part of the container, a 3D sensor, said 3D sensor being arranged in a position and with an orientation such that a field of view of the 3D sensor is oriented towards said content; - acquiring, by the 3D sensor, a depth map of a given resolution, said depth map including the whole or a portion of a surface of the content, and that may also include the whole or a portion of the interior walls of the container; and - computing, by a computing unit operatively connected to the 3D sensor: - a 3D surface model based on said given reference system by processing said acquired depth map and using said given position, orientation and field of view; and - a 3D level model by removing from the computed 3D surface model the points corresponding to the interior walls of the container, using a 3D function that searches the intersection or matching between the 3D surface model and the shape of the container, and filling in the missing points corresponding to the content that falls out of the field of view of the 3D sensor; and - using the computed 3D level model to compute the amount of content stored within the container, characterized in that: - the 3D sensor is a high-resolution and wide field-of-view 3D camera; and - said position and orientation are automatically adjusted using a 3D shape fitting function that fits the 3D surface model to the shape of the container. - attaching, on a top part of the container, a 3D sensor, said 3D sensor being arranged in a position and with an orientation such that a field of view of the 3D sensor is oriented towards said content; - acquiring, by the 3D sensor, a depth map of a given resolution, said depth map including the whole or a portion of a surface of the content, and that may also include the whole or a portion of the interior walls of the container; and - computing, by a computing unit operatively connected to the 3D sensor: - a 3D surface model based on said given reference system by processing said acquired depth map and using said given position, orientation and field of view; and - a 3D level model by removing from the computed 3D surface model the points corresponding to the interior walls of the container, using a 3D function that searches the intersection or matching between the 3D surface model and the shape of the container, and filling in the missing points corresponding to the content that falls out of the field of view of the 3D sensor; and - a 3D surface model based on said given reference system by processing said acquired depth map and using said given position, orientation and field of view; and - a 3D level model by removing from the computed 3D surface model the points corresponding to the interior walls of the container, using a 3D function that searches the intersection or matching between the 3D surface model and the shape of the container, and filling in the missing points corresponding to the content that falls out of the field of view of the 3D sensor; and - using the computed 3D level model to compute the amount of content stored within the container, - the 3D sensor is a high-resolution and wide field-of-view 3D camera; and - said position and orientation are automatically adjusted using a 3D shape fitting function that fits the 3D surface model to the shape of the container.