You've got to get that guest list number to your caterer, your venue, your uncle, your cat... everyone needs this number, right? How are you supposed to figure it out when you know your guests are slacking with their RSVPs?

The best way to guesstimate this number is to sit down with your list and figure out the likelihood of each person, but if you're needing the number NAONAONAO, we've got some math that may help. Here's our advice for how to estimate guest list numbers.

Your local guest numbers

Local guests are far more likely to come to your wedding. We'd suggest thinking 80-85%. If you have a hard maximum due to venue restrictions, you may want to err on the side of 85-90% just to be safe. Don't forget to count plus-ones and children, if they're invited.

Your out-of-town guests guest numbers

If out-of-towners aren't coming in internationally, you'll mostly be focusing on how close they are to you and if they've got the means to come, financially. If money isn't a big issue, account for about 70-75%.

If your wedding guest list is large and full of less close acquaintances, lower it to 40-50% attendance rate.

Destination weddings

Typically, attendance rates for destination weddings will be much lower, in the 30-40% range.

Now, let's math it out:

Let's err on the safe side and choose the larger of the numbers we mentioned before, assuming you're not having a destination wedding and that your out-of-towners can generally afford the trip:

(number of local guests x 90%) + (number of out-of-town guests x 75%) = total number of estimated guests

So if you have 120 people on your guest list, 30 of which are out-of-towners, and 90 are local, here's how it will play out:

(90 x 90%) + (30 x 75%)= approximately 104 guests

VOILA! You've now got a kinda sorta wonky number you can give out. Just know that you'll need to be diligent about watching the actual numbers roll in to be sure. This is no guaranteed number.

Ready your B List

B List guests are those who are on your secondary guest list as declines come in. You don't have to have this list, but it can definitely be helpful. Here's an excerpt from a post all about this:

What's that you say? Crotchety Aunt Begonia refused to attend because she's always hated your father? (Yay!) And best friend from out-of-town is going to be giving birth around that time? (Bummer.) There is only one way to celebrate or bounce back from a declined RSVP: Turn to your B-list! Guess who's getting an invite now... that new friend you made two months after you sent out your invites, and a couple of your partners' favorite co-workers.

A and B lists are often a part of wedding planning realities, and they don't speak for how much a couple cares for you. So snatch up those B list invites, and have a great time! Because Aunt Begonia wouldn't even come close to having the kind of fun you're about to have at your friend's wedding.

More sage guest list advice:

Do you have any other guest list estimation advice for us?