How the math works
Four numbers, one multiplication chain, no black box:
- Missed calls per month = calls per day × working days × the share you miss.
- Lost bookings = those missed calls × the share of answered calls that book.
- Recoverable revenue = lost bookings × the value of a booked patient or client.
That third step is where most ROI calculators quietly cheat. They multiply every missed call by the value of a booking, which assumes each one was a new patient ready to commit. They were not — some were existing patients rescheduling, some were suppliers, some hung up because they dialled wrong. So we ask for the booking rate instead of assuming it, and the number that comes out is one you can defend in front of a partner.
Where to get real inputs
- Calls per day and missed rate — your phone system already logs both. Most VoIP dashboards show answered vs missed for the last 30 days in a couple of clicks. Ten minutes here is worth more than any assumption we could supply.
- Value of a booked patient or client — use lifetime value if you track it, not the first appointment. A new dental patient is worth years of recall and hygiene visits; a personal-injury client is worth one case fee. These differ by an order of magnitude, which is why we did not hardcode a default we believed in.
- Booking rate — front-desk staff usually know this better than any report. Between 25% and 45% is typical for practices that take new-patient calls.
Where this number is wrong
Worth saying plainly, because you are going to check it anyway:
- It is gross, not net. Building and running the agent costs money. This figure is what comes back in, before that.
- It assumes the recovered calls are like your answered calls. After-hours callers may convert better (they are actively searching) or worse (they are price-shopping). We have seen both.
- It ignores capacity. If your calendar is already full, recovering dozens of bookings a month is not revenue — it is a waiting list, or a reason to hire. That is a good problem, but it is not this one.
- It counts new bookings only. It gives you nothing for the reschedules, recall calls, and routine questions the agent also absorbs, which is usually the larger share of call volume and the part that gives your front desk their day back.
If the output looks too good, lower the booking rate first. That is almost always the input people are most optimistic about.
Embed this calculator
Free to use on any site. We only ask that the attribution link stays in place.
<iframe src="https://aidevgen.org/ai-receptionist/roi-calculator/embed/"
width="100%" height="900" style="border:0;max-width:760px"
title="AI Receptionist ROI Calculator" loading="lazy"></iframe>
Related reading
- What an AI receptionist costs — what actually drives the build price.
- AI receptionist vs answering service — the honest comparison.
- Compare the options — AI, human, answering service, app.
- How it works, and for whom — the full overview.
- Dental practices · Medical offices · Law firms
Frequently asked questions
How accurate is this calculator?
It is an estimate, and it is only as good as the numbers you put in. The two inputs that move the result most are the percentage of calls you miss and the average value of a booked patient or client. If you are guessing at those, treat the output as a range rather than a figure. Your phone system's call logs will give you a real missed-call number in about ten minutes.
Why does it ask what share of answered calls actually book?
Because not every recovered call becomes revenue. Some callers are existing patients rescheduling, some are suppliers, some are asking a question and hanging up. Multiplying every missed call by the value of a booking is how these calculators end up producing numbers nobody believes. We ask for the booking rate so the result stays defensible.
What counts as a missed call?
Any inbound call nobody answered — rang out, hit voicemail, or was abandoned in a queue. Most practices underestimate this because voicemail feels like it was handled. It usually was not: the majority of callers who reach voicemail at a practice do not leave a message, they call the next number on the list.
Does the calculator account for what the AI receptionist costs?
No — it shows recovered revenue only, gross. We kept the cost out deliberately because a build price depends on your call flow, integrations, and volume, and baking a made-up figure into the model would make the output meaningless. Our pricing page explains what actually drives the number.
Can I use this calculator on my own site?
Yes. There is a copy-paste embed snippet further down the page. It is free to use on any site, commercial or not — we only ask that the attribution link back to this page stays in place.
Will the AI receptionist really answer every call?
It answers every call it receives, at any hour, with no queue. That is the honest part. What it will not do is convert callers a human could not have converted either — which is why the booking-rate input exists rather than being hardcoded to 100%.