>Hi,
>
>How can we know what is the height in pixel for each paper size and orientation selected for reports?
>
>Rgrds.

Pixel is device dependent measure. If you print in 300x300 dpi the height of an A4 sheet will be different if you print 600x600 dpi.
Having the resolution of the printing device you should convert the paper size (maybe in centimiters) to inches and then to dots (that are "pixels" in your case).

HTH