Printer shrinks my page

I'm relatively new to iMAC. I have a printer problem that I can't solve. I use Photoshop CS4 and am printing to an Epson Stylus Photo R210 Inkjet Printer. When I create an image - lets say and 8 inch x 8 inch, even when I turn off Shrink to Fit, my image always prints smaller than an 8 x 8. My printer is not an edge to edge printer but since the 8 x 8 easily fits inside an A4 size paper, it should print out to the full size. It happens with any photo I print regardless of the size. Always smaller. Can anyone help with this problem?

Does the same happen if you print from the Preview app ?

Printer

I tried the Preview App for printing and it's still impossible to get it to print out at the correct size. One thing I did try, which is putting me on the right track, is to copy the file (whatever the size) onto an A4 page in Photoshop first and then print. In Landscape View it printed the long side the exact size but shortened the short side. I'm wondering if I purchased an Edge to Edge printer it would stop that from happening!