Event Attendance Forecast & No-Show Calculator

How it works

Final registrations = registered so far ÷ share of the curve already in · share in = (1 − L) + L × (21 − days) ÷ 21 inside 21 days (L = late share), rising linearly from 50% to 100% of (1 − L) between day 60 and day 21 · attendance = final × (1 − no-show rate) · venue limit = capacity ÷ (1 − no-show rate) · guarantee = attendance × guarantee % (rounded up) · revenue = final registrations × average price

Registrations for most events arrive on a recognisable curve: a burst when sales open and at early-bird deadlines, a quieter middle, and a rush in the last three weeks. The calculator assumes that rush is about 30% of the final count for a typical paid conference, about 65% for a free or community event and 15% for an event that sells out early, and that the rest arrives evenly, half before 60 days out and half between 60 and 21 days. These shares reproduce published check-in data from more than a thousand events (PheedLoop): about 38% of paid-event and 69% of free-event registrations arrive in the last 30 days. Dividing today's count by the share that should be in gives the forecast final registrations. If you have past events, enter your own share instead; it beats any generic curve. Not everyone who registers turns up. As a rule of thumb free events lose 35 to 50% of registrants, low-cost tickets 15 to 25%, paid conferences 8 to 15% and invitation-only events with travel 3 to 8%, and you can enter your own rate. The no-show rate is what lets organisers accept more registrations than seats (capacity ÷ show rate), and it is what makes the catering guarantee a judgement call: caterers usually prepare 3 to 5% over the guarantee, so guaranteeing about 95% of expected attendance avoids paying for empty plates. Revenue counts every paid registration, including no-shows.

Worked example

With 320 paid registrations 21 days before a conference on a typical curve, 70% of sign-ups should be in, so the forecast is 320 ÷ 0.70 = 457 final registrations, 137 still to come (about 46 a week). At a 8–15% no-show rate (11.5% central), 389 to 421 people will attend, 405 expected. A 450-seat venue can take 450 ÷ 0.885 = 508 registrations at the expected rate, or 489 to be safe if only 8% skip. Guarantee the caterer 405 × 95% = 385 people three days out ($32,725 at $85 a head). Ticket revenue is about 457 × $295 = $134,857, with $40,457 still to come.

Sources: Eventbrite: ticket pricing strategies and attendance · PheedLoop Event Data Lab #05: no-show rates from 1,070 events (free vs paid, by size) · PheedLoop Event Data Lab #09: when registrations arrive and late-registrant no-shows · Nunify: event attendance-rate benchmarks (free vs paid, webinars)

Frequently asked questions