How many words can you fit on an A4 sheet?
One sentence contains an average of 11 words and one A4 sheet contains an average of 32 to 35 sentences. Therefore, an A4 sheet has an average of 350 to 400 words. However, this does apply to a relatively full A4 sheet with a standard layout and filled with 80 to 90% of text.
Microsoft Word offers a function that allows you to see how many words a document contains. The number of words can be checked by going to File -> Properties. This word count will not always be correct, since Microsoft Word does not count words in pictures or text boxes.