What are your page dimensions?

Our page sizes are in inches so they will have different pixels sizes depending on the monitor. Most monitors are 96 dpi. Apple computers with retina displays (such as Macbook Pros and iMacs) are 122 dpi. 

If you have a standard, 96 dpi monitor:

Letter (8.5 x 11): 816 x 1056
Legal (8.5 x 14): 816 x 1344
A4 (8.3 x 11.7): 797 x 1124

If you have a retina display monitor at 122 dpi:

Letter (8.5 x 11): 1037 x 1342
Legal (8.5 x 14): 1037 x 1708
A4 (8.3 x 11.7): 1013 x 1428