A quick and valid method for evaluating percentage body fat is based on the use of skinfold callipers. However, limitations associated to their use and characteristics led the authors to improve a traditional calliper (Harpenden) and to integrate it with a software application. Such a measuring system, LipoTool, is meant to have better accuracy and reliability, including data processing and digital recording at a very low cost. At first, a sample of 49 older adults was used to evaluate the performance of LipoTool by comparing its results to those obtained with the traditional Harpenden calliper. A strong positive association in %BF was achieved. This digital sensing system was later improved by incorporating wireless communication between the calliper and the software application, adding other functionalities. The software application works in any computer and is flexible to incorporate new coming models, linear regressions or new algorithms. This new system was validated against the standard Dual-Energy X-Ray Absorptiometry system, using a sample of 40 adults with positive results. This solution is a valid and reliable alternative to traditional reference callipers, simplifying the percentage of body fat evaluation and providing a more effective use in daily practice with less expenditure of time and resources. Its implemented guided procedure turns it into a precious training tool based on a non-invasive, portable device, and not requiring special individual preparation. Ongoing activities are focused on the design of a new mechanical structure, with novel functionalities and for exploring other studies.