What percentage of people bring a plus one?

About 60-75% of guests offered a plus-one will bring someone. Single guests are more likely to bring someone (70-80%) than those in established relationships who may already be invited as a couple. For casual parties the rate is lower (50-60%) as people feel less obligation.

Who should I offer a plus one to?

Traditionally, plus-ones go to guests in established relationships, guests who will not know anyone else at the event, and single guests at formal events. For casual parties, it is common to extend a general plus-one to everyone. For weddings, be selective due to cost and venue capacity.

How does offering plus-ones affect my budget?

Each attending plus-one adds the full per-guest cost for food, drink, and favours. If your per-head cost is £30 and 15 plus-ones attend, that is £450 extra (before any cost buffer). This calculator budgets for the plus-ones that actually turn up — accepted plus-ones less expected no-shows — and applies an optional cost buffer (default 1.1) on top for unexpected extras. Always factor in estimated plus-ones when setting your initial budget.

What is the no-show rate for plus-ones?

Even after someone accepts a plus-one, expect roughly 5-10% of confirmed guests to drop out at the last minute through illness or clashing plans. This calculator deducts a default 10% no-show rate from accepted plus-ones so your head count and catering budget reflect who actually attends. You can adjust the rate (0-50%) under Advanced Options.

Can I offer plus-ones to some guests but not others?

Yes, but be consistent with your criteria. Common rules: all guests in relationships get a plus-one, or only guests who know nobody else get one. Avoid offering to some single friends but not others in the same friend group.

Plus One Calculator — Extra Guest Estimates

Estimate how many additional guests will come when you offer plus-one invitations.

Total Invited (base)

Your confirmed headcount excluding plus-ones (the named guests on your list)

Plus-One Invites Offered

How many of those invitees you have allowed to bring a guest

Expected Accept Rate

Share of plus-one invites you expect to be taken up (typically 60-75%)

Cost per Guest (optional)

Your all-in cost per head (food, drink, favours) — used to estimate the extra spend from plus-ones

How We Calculate This

This calculator estimates how many plus-one guests will attend and the additional cost impact. It works from the plus-ones that accept, then deducts an expected no-show rate so your head count and budget reflect who actually turns up.

Formula

Expected plus-ones = plus-one invites × acceptance rate
Attending plus-ones = expected plus-ones − expected no-shows (default 10%)
Total expected guests = base invitees + attending plus-ones
Additional cost = attending plus-ones × cost per guest × cost buffer (default 1.1)
Guest count increase = attending plus-ones ÷ base invitees

No-show rate and cost buffer can be adjusted under Advanced Options.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Adjust quantities based on your guests and event type.