My FH and I finally picked a photo and nailed down the wording for our invites, and I need to order them this week. We currently have 64 households on our guest list, and I’m trying to determine if 75 will be enough or if I should order 80 just to be safe.
In my opinion, 75 should be enough. That's 64 households, one for yourself to keep, and 10 extra. If you total household count was higher, you'd want more extras, by percentage, but 10 extra is plenty.
I ordered at least 10 extra, and the company I ordered from included a few extra for free. It's good to have backups if people lose them, if some get bent or splashed or smudged, and you will probably want some as keepsakes for a shadow box or scrapbook or album, as might your parents/relatives.
It may depend who’s writing them out.. my mom did mine and only messed up on 2/50. I would recommend that you play around with the quantity on the sites though. I went with basicinvite.com and they were way cheaper in higher quantities.
I got 20 extra because I figured I would use one for the scrapbook, and if any get spilled on (we have cats) then it would probably ruin a couple of them, plus extras to hand out or mail out if we choose to its totally whatever you think is best
Personally, I would get extra and do 80 just in case. You never know! And typically based on experience, there is always more guests than planned. I would rather be safe than sorry. Not unless you can order additional invites later on if needed.
Some of our family members live in the same household but want their own invitation so they get to keep it as a memory as long as those 64 households are all good with only one invitation I believe that 75 would be enough.