Screen size and real size

I am new to sketchup.
I have a very simple question: when I draw 1 line of 1cm on the screen, I would like the measured value (the one that appears at the bottom right of the screen in Measurements) to be 10 cm. In my case, the displayed value is 123cm; where is this conversion done?

Sounds like you need to spend some time learning about using SketchUp. You model in real world dimensions. If you want to draw a line that is 10 cm long, start drawing it and enter 10 cm. It doesn’t matter how long it appears on the screen. That could vary depending on how much you are zoomed in with the camera.

Don’t measure the length of the line on the screen with a ruler.

Spend some time at

I think your question shows a fundamental misunderstanding of how SU works.

You give an edge (drawn using the Line tool) a real world length - say you want it to have a length in your model of 10cm.

This dimension will show in the Measurements box bottom right of the SU model window as you draw the line, or after you have typed a length of 10cm, 0.01m or 100mm while drawing the edge/line.

How big it appears on the screen depends entirely on how you are looking at it. Zoom in or out, or orbit to look at it look from a different direction, and it will take up ANY number of pixels from 1 (when you zoom out so it seems almost to disappear in the distance) to extending to the edges of your screen, with the ends off screen.

View the tutorials at to get a clear idea of how SU works.

[As usual, @DaveR types faster than I do on my phone!]

Thank you very much for your reply.
I have now understood the principle.