Currently, many customers and broadband providers are using cloud resources, such as processing and storage, for their applications and services. With the increase of computational resources usage, elasticity has become quite attractive and a key feature in cloud computing paradigm. However, due to many technologies and strategies for providing cloud elasticity, its measurement is not obvious. Here we propose a set of metrics for measuring cloud computing elasticity based on Physics' concepts, such as strain and stress, and Microeconomics. Our experimental results show the proposed elasticity metrics behave well towards the CPU usage. Besides, the metrics computation is simpler because it is straightforward, which speeds up the cloud elasticity evaluation.