Finding a boot that fits comfortably in a ski rental shop can be a difficult and tedious task for many people. Having properly fitting boots is important to prevent injuries in the user and reduce the risk of accidents happening on the mountain. The goal of this master thesis was to develop a tool that could make it easier for the customers in a ski rental shop to find the right boot for them. This was done by first sending out surveys to students at LTU and Swedish rental stores and interviewing rental store staff. It was found that a lot of the students don’t want to take the time to properly test their boots in the shop and that the staff don’t feel like they have the time to properly measure and fit every customer with a proper set of boots. It was theorised that making the measuring of the foot easier, faster, and more thorough would increase the chances of customers finding the right set of boots. The measurements that need to be taken for a proper boot matching to be made were found to be foot length, foot width, instep height, and calf volume. Through a design process combining a convergent/divergent and an iterative phase a tool that can take these measurements was designed and developed. The tool is a sock with built in stretch sensors that align themselves on the user’s foot in the correct places as the user puts on the sock. With a microcontroller the sock takes the measurements and sends them wirelessly to a screen that is placed in the store making it easy for the user to read the measurements. On the screen the user can also see what boot they are recommended to rent based on the measurements and book them directly on the screen.