PartyCalcs.uk
RSVP Calculator — Track Guest Responses
Estimate how many guests will actually attend based on your RSVP responses.
How We Calculate This
This calculator helps you estimate total attendance by combining confirmed RSVPs with predictions for non-responders.
How it calculates
- Still waiting = total invited − accepted − declined − no reply yet (the leftover gap, never below zero)
- Response rate = (accepted + declined) ÷ total invited × 100
- Acceptance rate = accepted ÷ responded × 100
- Estimated from non-replies = (no reply yet + still waiting) × no-reply attendance rate (default 45%)
- Total expected = confirmed yes + estimated from non-replies + (confirmed yes × planning buffer%)
The no-reply attendance rate and planning buffer are adjustable under Advanced options. The 45% default for non-responders is a middle ground based on event-planner guidance (The Knot / RSVPify): plan for roughly 80–85% acceptance, and assume about 40–50% of non-responders attend casual events, 30–40% for formal ones. The planning buffer (default 0%) adds a small allowance on top of confirmed guests for unexpected plus-ones.
Frequently Asked Questions
For formal events with RSVP cards, 80-90% of guests respond. For casual events with informal RSVPs (text, email), only 50-70% respond. Wedding RSVPs typically get 85-95% response rates. Following up with non-responders significantly improves response rates.
About 40-50% of non-responders typically show up to casual events; for formal events about 30-40% attend. As a sanity check, industry data (The Knot, RSVPify) shows roughly 80-85% of all invitees accept and around 83% ultimately attend, so this calculator defaults to a 45% non-responder attendance rate as a defensible midpoint. It is always best to follow up directly with anyone who has not responded rather than guessing.
Set the RSVP deadline 2-3 weeks before the event for casual parties, and 4-6 weeks before for weddings or catered events. This gives you time to chase non-responders and finalise numbers with caterers and venues.
Send a friendly reminder 1 week after the RSVP deadline. A personal text or call works better than a group message. Phrase it as needing to confirm numbers for catering rather than chasing them. Most people simply forgot rather than deliberately ignoring the invite.
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Last updated: February 2026
All calculations are estimates. Adjust quantities based on your guests and event type.