Party Invitation Count Calculator
Decide how many invitations to send given expected RSVP and no-show rates.
Last updated · View algorithm, constants and default inputs (JSON)
About this calculator
Estimate invitations from your target attendance and the acceptance, plus-one and no-show rates you enter. These rates vary by event and guest list; the result is a scenario, not a universal over-invitation rule.
Worked example
calculated with the default values below
Guests you want to attend 60 · Expected acceptance rate 70 % · Expected no-show rate 10 % · Guests bringing a plus one 20 % Invitations to send 80 · Expected invitees accepting, including estimated plus-ones 67 · Expected actual attendees 60 · Expected no-shows 7 · Illustrative 5% seat buffer 3
General background references
Disclaimer
These calculators give general estimates. Sizing, pricing, availability and standards vary by brand, retailer and country, so treat the output as a starting point and confirm it against the seller's or authority's own figures.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
I = ceil(T ÷ (a (1 + p ÷ 100) (1 − n ÷ 100))); E = I a (1 + p ÷ 100) (1 − n ÷ 100)
- T
- Target attendees
- a
- RSVP acceptance rate (%)
- p
- Plus-one percentage
- n
- No-show percentage
- I
- Invitations to send
- E
- Expected actual attendees
Invites = ceil(target attendance / (acceptance rate × (1 + plus-one rate) × (1 − no-show rate))). Expected acceptances include estimated plus-ones; attendees then apply the no-show rate. Seat buffer is a separate illustrative 5% of the target, not an optimized venue capacity.
Frequently asked questions
Why do I need to invite more than sixty people to fill sixty seats?
Not everyone accepts and some who accept do not show, so the tool divides your target by the per-invite yield. With 70% acceptance, 10% no-show and 20% bringing a plus-one, each invite yields about 0.756 attendees, so 60 desired becomes 80 invitations, expecting roughly 67 acceptances and about 60 actual arrivals. The spare-seats figure covers the jitter from these rates.