Abstract: The invention provides a computer-implemented method of detecting a liquid level inside a container, the method comprising the steps of: capturing, by a camera of a portable device, a first image of the container; providing the first image to an input layer of a convolutional neural network, CNN; obtaining, from a final layer of the CNN, the liquid level inside the container in the first image; and storing the obtained liquid level, wherein the CNN is configured to identify features of a plurality of volume indicators of the container in the first image and determine the liquid level in the container in the first image based on the identified features.