So in our infinite wisdom, we ordered an invitation per guest! Sounds great right? Until I started addressing them and it dawned on me that DUH most of our friends/people were are inviting are couples...so that would be 1 invite per 2 people, or more if they have kids.
We pretty much ordered twice as many invitations as we actually needed. Which really sucks because what a waste of money! And now we have a lifetime supply of envelopes that are square lol.
Make sure you take a look at your guest list and count how many invitations you actually will need, don't just take the number of people and order that many!