No-Show Rate Formula: How to Calculate It, and What to Do About Late Cancellations

Open the no-show rate calculatorDownload the monthly no-show tracking sheet (PDF)

The formula

No-show rate = no-shows ÷ appointments booked × 100. Eight no-shows out of 100 appointments booked is an 8% no-show rate. The no-show rate calculator does this division and then works out what the empty slots cost.

Two parts of that sentence need defining before the number means anything: which appointments count as "booked", and what counts as a "no-show". Get them wrong, or change them from month to month, and the rate moves for reasons that have nothing to do with your customers.

Divide by booked, not by kept

The most common mistake is dividing by the appointments that actually happened. The no-shows have to be part of the total, because the rate is the share of booked appointments that were missed.

The difference grows as the rate does. With 20 no-shows out of 100 booked, dividing by booked gives 20%. Dividing by the 80 that were kept gives 25%, a figure that makes things look worse than they are and will not match anyone else's method.

Hotels and airlines use their own definitions for reservations and seats, so a "no-show percentage" from those industries may not be built the same way. For appointments, divide by booked.

What counts as booked, and the late-cancellation question

An appointment cancelled a week ahead is not a problem: you had time to give the slot to someone else. One cancelled an hour before is, in practice, a no-show with better manners. So set a cancellation cut-off, the notice you need to refill a slot (24 hours is common for one-to-one services), and use it to sort every booking:

• Cancelled before the cut-off: leave it out entirely. It is not "booked" for this purpose.
• Kept: booked, and the person came.
• Late cancellation: booked, cancelled after the cut-off.
• No-show: booked, did not come, did not cancel.

Then track two numbers. Your no-show rate is no-shows ÷ booked. Your lost-slot rate is no-shows plus late cancellations ÷ booked. The first tells you about people who forgot or did not care; the second tells you what the empty chair actually cost. Keeping them apart stops a change in one hiding a change in the other.

A worked month

A massage therapist's calendar for one month started with 140 bookings. Twelve were cancelled more than 24 hours ahead, so 128 count as booked. Of those, 114 were kept, 9 were no-shows and 5 were cancelled with less than 24 hours' notice.

• No-show rate: 9 ÷ 128 = 7.0%
• Lost-slot rate: (9 + 5) ÷ 128 = 10.9%
• Dividing by kept instead: 9 ÷ 114 = 7.9%, the wrong number

At $90 an appointment, the 9 no-shows cost $810 a month, $9,720 a year. Counting the late cancellations nobody could fill, 14 empty slots cost $1,260 a month. Open the calculator with the no-show figures, then change no-shows to 14 to see the lost-slot cost.

How to calculate yours, step by step

1. Choose a full month

A whole calendar month, so next month's figure compares fairly. The video above shows a month view and where each appointment's status is set.

2. Set your cut-off

The notice you need to refill a slot. Write it on the tracking sheet with this post and keep it the same.

3. Count appointments booked

Everything still on the calendar once the cut-off passed, including no-shows and late cancellations.

4. Count no-shows and late cancellations separately

The easiest way is to mark each appointment's outcome on the day. In Fynl's Appointments list every booking has a status (Showed, No-show or Cancelled) and the list can be filtered, so the month's count is a filter rather than a search through your memory.

5. Divide

No-shows ÷ booked × 100, and no-shows plus late cancellations ÷ booked × 100.

6. Track it monthly

One month is a snapshot; the trend is what matters. If you can, split by service, day of the week, and new versus returning clients. Our guide to setting up booking for a small business covers the cut-off and deposit decisions that feed into these numbers.

Reading the change from month to month

With small numbers, the rate jumps around. A business with 60 bookings a month moves 1.7 percentage points for every single no-show, so going from 4 to 6 no-shows looks like a leap from 6.7% to 10% when it may be nothing more than a bad week. Before reacting:

• Look at three months together as well as the single month. Add up the booked and no-show counts, then divide, rather than averaging three percentages.
• Check the counts, not just the rate. If bookings fell sharply, the same number of no-shows makes a bigger rate.
• Note anything unusual on the tracking sheet: a holiday week, a storm, a new service, a change to reminders. It is the only way to explain a jump later.

Two edge cases

Very late arrivals. Someone who turns up 40 minutes into a 60-minute appointment may cost you as much as a no-show. Decide a lateness rule once (for example, more than 15 minutes late counts as a no-show if the appointment cannot go ahead) and write it on the sheet.

Refilled slots. If you fill a no-show's slot from a waiting list, it still counts as a no-show in the rate, because the person did not come. It just costs you less. The calculator assumes every no-show is an empty slot, so lower the number you enter for cost if you often refill.

For context on how your rate compares, published research is mostly from healthcare; a 2018 systematic review of 105 studies put the average no-show rate there at around 23% (Dantas and colleagues, Health Policy). Your own trend is the more useful comparison.

The calculator sits alongside a free booking page and form builder on our free tools page.

Questions people also ask

Sources

• Dantas et al., No-shows in appointment scheduling: a systematic literature review, Health Policy (2018)
• Kheirkhah et al., Prevalence, predictors and economic consequences of no-shows, BMC Health Services Research (2016)