The No-Show Calculator: What a 7% DNA Rate Costs a Three-Practitioner Clinic

Most clinic owners know their DNA rate roughly and their monthly revenue precisely, and rarely put the two together. The no-show calculator does the multiplication from three numbers you already have. This post walks through it for a typical three-practitioner clinic, shows the result in pounds, dollars and dirhams, explains where the number is wrong in both directions, and works out what moving the rate is actually worth.

The clinic

A physiotherapy, osteopathy or similar private clinic with three practitioners, each seeing 60 patients a week, so 180 appointments a week across the diary. Last quarter's DNA rate, measured as appointments missed without notice divided by appointments booked, was 7%. The average value of an appointment, taking initial assessments and follow-ups together, is £60, which we will also run at $80 and AED 250 for clinics in the US and the UAE. Those are typical private-clinic figures, not benchmarks; the point of the calculator is to use your own.

The maths

The calculator is deliberately simple, and it is worth seeing why.

Missed appointments a month = appointments per week × DNA rate × 52 ÷ 12

= 180 × 0.07 × 4.33 = 55 missed appointments a month

Cost a month = missed appointments × average appointment value

Cost a year = cost a month × 12

Currency	Appointment value	Cost a month	Cost a year
GBP	£60	£3,300	£39,600
USD	$80	$4,400	$52,800
AED	AED 250	AED 13,750	AED 165,000

Fifty-five empty slots a month, about 650 a year, from a rate most owners would describe as "fine". The currency switch on the calculator changes the formatting only; the 55 does not move.

Where the number is too low

The calculator understates the cost in at least four ways, on purpose, because each of them depends on the clinic:

1. The clinician's time. A missed slot is paid time with nobody in it. The calculator counts lost revenue, not the cost of the practitioner sitting there.
2. The patient who could not get in. Every DNA was a slot somebody else wanted. In a clinic with a waiting list, the cost includes the patient who went elsewhere.
3. Downstream appointments. A missed initial assessment is often a missed course of treatment, not one appointment.
4. Admin. Chasing, rebooking and the phone call afterwards all cost reception time.

NHS England has put a figure on one piece of this for general practice, estimating each missed GP appointment at around £30 before the wait for the next patient is counted. For a private clinic the equivalent figure is yours to work out, and it is always higher than the slot value alone.

Where the number is too high

Two corrections in the other direction:

1. Late cancellations are not DNAs. If your 7% includes cancellations inside the notice period, some of those slots were refilled from a waitlist and cost nothing. Run the calculator with true DNAs for the floor and with late cancellations added for the ceiling.
2. Not every missed slot is a lost appointment. A patient who misses a follow-up and rebooks has delayed revenue, not lost it, if the diary had room. In a full diary the loss is real; in a half-empty one it is partly timing.

This is why the calculator stops at the multiplication and adds no recovery estimate. Any figure beyond that is a claim, and the honest figure is yours.

What moving the rate is worth

The HMDG barometer of 715 UK private clinic owners found a 6.3% DNA rate at clinics with automated reminders against 11% without, and the Cochrane review found attendance rising from 67.8% to 78.6% with text reminders. Suppose this clinic gets from 7% to 4% with reminders patients can reply to, self-service rebooking and a deposit on initial assessments.

DNA rate	Missed a month	GBP a month	USD a month	AED a month
7%	55	£3,300	$4,400	AED 13,750
4%	31	£1,860	$2,480	AED 7,750
Difference	23	£1,440	$1,920	AED 6,000

Twenty-three appointments a month recovered, about 280 a year. That is the figure to hold any reminder setup against: the cost per recovered appointment is what you spend divided by 23, and the comparison is with the empty slot, not with doing nothing.

Running it for your clinic

Three numbers from last month:

• Appointments per week. Count every booked appointment across clinicians and rooms for a typical week. For a group, run it per site and then for the group.
• DNA rate. Missed without notice ÷ booked, as a percentage, over the same period. Keep late cancellations in a separate column.
• Average appointment value. Revenue per appointment in the currency you bill in. If initial assessments and follow-ups differ a lot, use a weighted average or run the calculator per appointment type.

Then run it twice: with the DNA rate you have, and with the rate you think reminders, self-service rebooking and deposits could get you to. The difference is the budget.

A second example: the single-practitioner clinic

The same arithmetic at a smaller scale is, if anything, more pointed, because every missed slot is a bigger share of the week. Take a solo counsellor or physiotherapist seeing 25 patients a week with the same 7% DNA rate and a £60 appointment value.

	Per month	Per year
Missed appointments	8	91
GBP	£480	£5,460
USD (at $80)	$640	$7,280
AED (at AED 250)	AED 2,000	AED 22,750

Eight missed appointments a month in a 25-a-week diary is two working days of sessions each month with nobody in the room. For a solo practitioner that is also two days of paid time, which the calculator does not count, and the waiting list of patients who could have had those slots. Bring the rate to 4% and the recovery is about three appointments a month, roughly 36 a year, which for a practice that size is most of a month's income over the year.

The other thing the small example shows is how little margin there is for measurement error. One DNA in a week is 4%; two is 8%. Measure over a quarter, not a week, before deciding whether the rate has moved.

Reading the result honestly

A few habits keep the number useful rather than alarming:

• Use the same definition every month. Missed without notice, divided by booked. If reception starts logging late cancellations as DNAs, the rate climbs without anything changing.
• Watch the trend, not the month. A bad week in August is not a trend; three months of the same pattern is.
• Break it down before you act. The overall rate tells you how big the problem is. The rate by clinician, appointment type and weekday tells you which reminder rule, which deposit setting or which booking lead time to change.
• Judge changes by recovered appointments. The cost per recovered appointment, what you spend divided by the appointments you now keep, is the figure that decides whether a reminder setup is working.

What reduces the rate

In order of evidence and effect: automated reminders with a one-tap reply, a first reminder early enough to rearrange, self-service rebooking so patients can move a slot without phoning, deposits for the appointment types where a miss is expensive, a waitlist that fills freed slots, and a monthly DNA report by clinician and appointment type so you fix the pattern rather than the average. The guide on how to reduce DNAs covers each step, and the appointment reminder software page shows how the sequence runs itself.

Capra runs all of it from one place: reminders and replies, rebooking, deposits, the waitlist and the DNA report, with the calculator built into the reminders page so you can keep the number in front of you. Put your own figures in, and if the result is a number you would rather not look at, a demo is the next step.