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 plus-one adds the full per-guest cost for food, drink, and favours. If your per-head cost is £30 and 15 plus-ones accept, that is £450 extra. Always factor in estimated plus-ones when setting your initial budget.

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.

PartyCalcs

Plus One Calculator — Extra Guest Estimates

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

Total Invited (base)

Plus-One Invites Offered

Expected Accept Rate

Cost per Guest (optional)

How We Calculate This

This calculator estimates how many plus-one guests will attend and the additional cost impact.

Formula

Expected plus-ones = plus-one invites x acceptance rate
Total expected guests = base invitees + expected plus-ones
Additional cost = expected plus-ones x cost per guest

Frequently Asked Questions

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Last updated: February 2026

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