Simply measure your screen
With the help of a normal credit card, you can measure your screen here.
1. Place card
Place a real credit card flat on the image of the credit card.
2. Resize card
Move the buttons and until the picture and the real map are exactly the same size.
3. Choose size
Pay attention to the correct size and then click on the number next to the red arrow. If there is no suitable size, stop the measurement with ESC.