Calibration is a technique that is commonly used in science and engineering research that requires calibrating measurement tools for obtaining more accurate measurements. It is an important technique in various industries. In many situations, calibration is an application of linear regression, and is a good topic to be included when explaining and learning the concepts of linear regression. However, calibration is not often mentioned in the introductory statistics textbooks or in the introductory statistics classrooms. The goal of this paper is to share with instructors an example with real data for simple linear regression and its application in calibration. It can be used as a lecture example, a class project, or a lab activity. (Contains 10 figures and 3 tables.)