[free] I built a Wedding Attendance Calculator because the standard "expect 20% to decline" rule is actually wrong (and can blow your budget).

I see so many posts on here of people stressing over B-lists, strict micro-wedding packages, and whether they can safely invite 75 people when their budget and venue absolutely max out at 60.

When I was trying to figure this out, everyone just kept repeating "expect 15-20% of people to decline." But as a data person, that drove me crazy because a local Saturday wedding in the Spring is going to have a way different drop-off rate than a destination wedding on a Sunday in the Winter.

When you are trying to keep the entire wedding under $10k, over-inviting and getting that math wrong by even 5 or 10 people can completely derail your catering costs and force you to cut corners somewhere else.

I ended up diving into the actual industry data and built a strictly utilitarian calculator to do the exact math for this.

Instead of a flat 20%, the math actually shifts based on modifiers:

• Base rates: Local is ~85% attendance, Destination is ~65%.
• Day of the week: Saturdays are the baseline. Fridays drop by 3%, Sundays drop by 8%, and weekdays drop by 15%.
• Season: Spring/Fall are the baseline. Summer drops by 3% (vacation conflicts) and Winter drops by 7% (weather/holidays).

I actually built a free web calculator that does all this math for you and gives you a 'safe buffer' number. It also has a "Fill my venue" mode where you type in your hard budget limit or venue capacity (e.g., 60 people), and it tells you exactly how many invitations you can safely send out without going over.

It’s completely free to use. There is no email signup, no paywall, and no ads. It's just a raw calculator I built to solve this exact headache.

Here is the direct link: https://www.idotogether.com/tools/rsvp-estimator

For those already married or past their RSVP deadline—what was your actual drop-off percentage? Curious to see if the season/day math holds up for everyone else!