The installation language determines which system of measurement is used for the application. However, you can display the media sizes using a different system of measurement.
Click [System] - [System of measurement for media].
Select which system of measurement you want to use to display the media sizes.
For example, A4 will be displayed in inches instead of millimeters when you select [System of measurement for media] = [Imperial (Letter, 11" x 17", etc.)].
Click [Save].