This book provides a complete guide for calculating the measurement uncertainty associated with tests performed using an analog universal calliper. The purpose of this book is to provide, to all those who take measurements, a simple and quick way to evaluate the uncertainty, contributing to the traceability of the measurement results and demonstrating its reliability.To do this, the following steps were performed: study of the measuring system composed of the caliper, emphasizing the operating principle, application and constructive characteristics; identification of the variables that influence the measurement result of each measurand; mathematical modeling of the measurement process in question, as recommended by GUM (2003); implementation of the uncertainty calculation scripts using the Excel program; execution of the tests to obtain the necessary data for simulation, uncertainty evaluation with the respective discussions and, finally, validation of the spreadsheets. Excel proved to be a powerful tool for the implementation of the calculation scripts to obtain measurement uncertainty.