No-Show Cost Calculator
Put a monthly figure on missed appointments and model what a reminder sequence recovers. Accounts for the slot that cannot be resold, the staff time already committed, and the cost of the reminders themselves.
An empty slot costs more than the appointment fee, because the staff time was committed anyway. Enter your booking volume, no-show rate and slot value to see the monthly loss and what a reminder sequence would need to achieve to pay for itself.
What this tool does
Enter your monthly appointment volume, your current no-show rate, the average value of a booked slot and the staff cost of the time held for it. The calculator returns the direct monthly loss, then models a reminder sequence: how many no-shows a given reduction in the rate would recover, what the messaging costs to send, and the net position.
The staff cost line matters. A missed appointment is not just lost revenue — the room, the chair and the person were all paid for regardless. Counting only the fee understates the loss.
A worked example
A practice books 400 appointments a month with an average value of £85 and a no-show rate of 12%. That is 48 empty slots.
The direct revenue loss is straightforward. Add the staff time held for those 48 slots and the figure grows again. Then consider that some proportion could have been filled from a waiting list had you known in time — which is what a reminder sequence with a confirm-or-cancel reply actually buys you. A cancellation 24 hours out is a slot you can resell. A no-show at 10am is not.
Model a reduction from 12% to 7%. That is 20 slots recovered a month. Against a reminder cost of two or three SMS segments per booking across all 400 bookings, the sequence usually pays for itself several times over — but the calculator makes you prove it rather than assume it.
What to include
| Line | Why it counts |
|---|---|
| Appointment value | The revenue that did not arrive |
| Staff time held | Paid whether or not the client attended |
| Room or equipment | Fixed cost, allocated to a slot that earned nothing |
| Resale opportunity | Only recoverable with enough notice |
| Reminder cost | The messaging you send to all bookings, not just the risky ones |
Where people go wrong
Counting only the fee. The fee is the smallest part. Committed staff time usually exceeds it once you allocate honestly.
Sending one reminder. A single message the day before catches the forgetful and nobody else. A sequence — confirmation at booking, reminder 48 hours out, reminder on the morning — performs differently to each of those groups.
Not offering a cancel path. A reminder that cannot be replied to converts a no-show into a no-show who feels nagged. A reminder with a one-tap cancel converts it into a slot you can refill.
Ignoring the message cost across the whole book. You send reminders to everyone, including the 88% who would have attended anyway. Cost the whole volume — check your segment count with the SMS segment calculator and the total with the Twilio cost calculator.
Modelling an unrealistic reduction. Reminder sequences reduce no-shows; they do not eliminate them. Model a modest improvement and let the result be genuinely surprising rather than flattering.
FAQ
What no-show rate should I use?
Your own, from your booking system. Industry averages vary so widely by sector, appointment type and lead time that borrowing one produces a number you cannot defend to anybody.
Do SMS reminders beat email?
For time-sensitive reminders, generally yes, because they are read within minutes rather than hours. Email is better for the initial confirmation with the detail attached. Most practices end up using both.
Should I take deposits instead?
Deposits are the single most effective intervention and also the one most likely to reduce bookings. Reminders are the low-friction option; deposits are the high-commitment one. Model both.
How far ahead should the reminder go?
Far enough that the slot can be resold. Twenty-four hours is the usual minimum, forty-eight if your waiting list is thin.
Does this work for sales calls as well as appointments?
Yes. Replace the appointment value with your average deal value multiplied by close rate, and the same arithmetic applies.
Next steps
AI for Appointment-Based Businesses covers the booking and reminder flow end to end, and GoHighLevel SMS Automation covers building the sequence itself. If the calls behind those bookings are also being missed, the missed call revenue calculator is the companion figure.
For a sense of scale beyond your own diary, NHS England estimates eight million missed hospital appointments a year in England at an annual cost of around £1.2bn, and the trust piloting predictive booking was running an 8% did-not-attend rate (NHS England). If you are building the reminders yourself rather than buying them, Twilio's message scheduling documentation covers queuing a send up to 35 days ahead, which is tidier than a cron job firing at 3am.
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