Strange, unless you have images or special text features. Are the document using the same layout,margins and spacing? Does one have a table of contents and the other does not? the only other thing would be if one document has large technical words with 10 to 12 letter each and the other rarely hist 5 or 6 . But a difference that is that large my bet is on a hidden image or some thing else. Try highlighting everything (ctrl A) in the larger document so it will show everything. This may expose it.