How do I set the image size in PS touch to print to my Epson printer w ithout losing any of the picture. PS Touch appears to be showing pixels and not inches, how can I covert it toshow inches?

I am using PS Touch from my tablet . I am importinga photo from an SD card . When all editing is completed I then send it wireless from the tablet  via Epson I print to the printer. It all works great except that part of the photo at each end is cut off and does not print. I am printing on 8.5 x11 paper.

How do I convert the image size in PSTouch frm pixels to inches?