I have just pasted the same snippet of text into both MS Word 2010 and Scrivener for Windows. In MS Word it says word count is 1,118. In Scrivener word count is 1,143. It is a difference of 228 words (20%), which is quite significant, as I need to write a 100,000 word document, so I don’t want to find out at the end that I only have 80,0000 words.
What is the reason behind this difference? Is there a way to have the same word count in both software? I have checked and there is no other text in that Scrivener document, so I’m baffled as to how it can show 20% more words.
A lot of different word-count algorithms are used across different programs, so it’s doubtful you could get the exact same count in different places across a sample of documents. Word doesn’t count hyphenated words or words separated by an ellipsis as two words, which Scrivener does, so that may make up a chunk of your difference. (On the other hand, Scrivener won’t count symbols like “***” as a word, whereas Word will.) Where you’re getting the word count from in Scrivener can make a difference too–the count in the editor footer will include inline notes, so if you have comments on the text that imported, they’ll be getting added to the word count here. Project > Project Statistics is the best count for when you’re bringing work out of Scrivener, as it uses your compile settings, meaning that you can exclude annotations or that it may add to the word count you’d see in the document if you’re compiling titles or title prefixes (“Chapter One” etc.). That text will of course then appear in the document when you open it in Word, but when copy/pasting the other direction you might be picking up some extra words from that right now.
Unless I am missing something (which is entirely likely), that is only a 2% difference. Still an annoyance, although MM’s explanation makes sense.
Jennifer, thank you for the explanation, and 47.7N116.9W, thank you for spotting my mistake. I pressed the wrong key on my calculator, and it was late at night. (OK, I’m rubbish at maths 
a 2% margin of error I can live with…