Chest X-ray is still nowadays the most commonly used imaging modality worldwide. Paradoxically, it is less and less taught today. As cross-sectional imaging has become increasingly efficient, rapid, and accessible, education in chest radiography has declined proportionately, both in quantity and quality. Furthermore, in institutions where chest X-ray is still taught, students are hardly trained to make measurements on plain radiographs. The only measure that is still universally performed is the cardiothoracic ratio, though it is often roughly estimated in clinical routine practice. This chapter proposes to revisit a certain number of measurements and indexes of frontal and lateral chest X-rays, some still used, and others somewhat fallen into disuse. It is an opportunity to discuss the diagnostic value of each of these metrics, and tentatively raise renewed interest in some of them.