Screen image size calculating for printing.

[yottie]

Is there a simple formula to enable me to calculate the screen image I see to the actual print-out size (@ 300 dpi)
To sum up:
I intend to take a pic of a badge, open the jpeg, transfer the badge to iron on transfer paper, to emerge at the same size as the original badge.

 

[foxhole]

There is no correlation between screen image and print image, that is handled in print settings.

 

[tomfe]

You can just use number of pixels to work out the size.
http://www.vesterkopi.dk/en/help/562-convert-pixels-to-cm.html

 

[yottie]

Thanks tf, that seems to be what I'm after.