AI Receptionist ROI Calculator: Estimate What Missed Calls Cost You

Missed calls are easy to shrug off because you never see what they would have been worth. This calculator puts a rough number on it using only your numbers: how many calls and inquiries you get, how many go unanswered, how many of those would have booked and what a typical job or client is worth. It estimates the revenue at risk each month and each year, and shows how that compares with a 30-Day Installation from AI Business Harness, a managed AI workflow service.

It runs in your browser. There’s no email gate, and nothing you type is sent anywhere or saved.

Missed call cost calculator

Prefer to have it built for you? AI Business Harness is a managed service that builds and runs workflows like this on the software you already use, with human approval on important actions. Book a 20-minute Fit Call, or talk to the live voice demo to hear our AI front desk first.

How the math works

1. Missed inquiries per month = calls and inquiries per week × percent missed ÷ 100 × 4.33. (4.33 is 52 weeks ÷ 12 months.)
2. Bookings missed per month = missed inquiries per month × percent that would have booked ÷ 100.
3. Revenue at risk per month = bookings missed per month × average job or client value.
4. Revenue at risk per year = revenue at risk per month × 12.
5. Installation comparison = $5,000 ÷ revenue at risk per month: roughly how many months of estimated revenue at risk the 30-Day Installation's starting price represents.

A worked example with the made-up example numbers: 30 calls a week × 20% missed × 4.33 = 26 missed inquiries a month. If 20% of those would have booked, that’s 5.2 bookings. At $300 each, it’s $1,560 a month, or $18,720 a year, of revenue at risk, and $5,000 is about 3.2 months of that.

A note on scale. This calculator is a supplementary check: it only estimates missed-call revenue. The AI front desk is usually the first workflow, not the whole service. The managed service (AI Operations Partner, from $5,000 a month) is sized for businesses where after-hours and routine inquiry volume, plus additional approved workflows such as follow-up preparation, intake and request routing, justify it. A 30-Day Installation measures those against your own baseline, including staff time, delayed handoffs and follow-ups. See AI front desk by industry.

The optional answering cost is shown next to the estimate for reference only. The calculator doesn’t subtract it or assume an AI receptionist replaces it. Blank, negative or out-of-range entries (percentages above 100) aren’t calculated; you’ll see what to fix instead.

What this doesn’t capture

• Revenue isn’t profit. The estimate leaves out what it costs you to do the work.
• Not every missed caller is lost. Some call back, leave a voicemail you return or book another way. Others would never have booked.
• An AI receptionist won’t recover all of it. Some callers hang up on any automated answer or want a person, and some questions need your team.
• Repeat work and referrals. Losing a first job can also mean losing later work. The estimate leaves that out.
• Your percentages are guesses until you measure them. In a 30-Day Installation, we measure the baseline before building anything.
• Costs beyond the Installation. Third-party software and usage are billed separately, and ongoing managed operations are from $5,000 a month if you continue.

Where to find your numbers

Most phone systems and VoIP providers show missed, abandoned and after-hours calls in a call log or report. For the booking rate, look at how many answered inquiries turned into jobs or clients over the last few months. For value, use the average invoice or the first-year value of a new client, whichever you’d actually lose if the caller went elsewhere.

If the number is worth acting on

Hear what an AI front desk sounds like first: talk to the live voice demo. For the options side by side, read AI receptionist vs. answering service vs. managed AI workflow, and for what the 30-Day Installation includes, see what the 30-Day Installation includes. When you’re ready, book a 20-minute Fit Call and bring your numbers. We’ll tell you honestly if it isn’t worth automating.

Related industry guides

• After-Hours AI Answering for HVAC and Plumbing: What It Should Say at 2 a.m.: after-hours calls, emergencies first, and dispatch without promises.
• AI Receptionist for Dental Offices: A Careful Setup Checklist: a careful setup checklist for a single practice.
• AI Intake for Law Firms: What It Can Do, and What It Must Never Say: the intake basics for a single office: conflicts, consultations and the off-limits list.
• AI Intake for Personal Injury Law Firms: Answer Every Call, Promise Nothing: after-hours injury calls handled with no case evaluations or deadline advice.
• AI Receptionist for Property Management: Maintenance Calls, Showings and Fair Housing: maintenance emergencies, tenant calls and owner questions.
• AI Inquiry Handling for Real Estate Agents and Brokerages: Fast Response Without Fair Housing Risk: fast lead response with the same questions for every caller.
• AI Front Desk for Multi-Location Med Spas: Consult Requests Without Clinical Promises: consultation requests by location, with treatment questions kept with providers.
• AI Inquiry Handling for Home Builders and Remodelers: Sales Leads and Warranty Requests: sales inquiries and warranty requests, sorted and documented.

Frequently asked questions

Is this AI receptionist ROI calculator free?

Yes. There's no email gate and no sign-up. It runs in your browser, and the numbers you enter aren't sent to us or saved.

Where do the example numbers come from?

We made them up to show how the calculator works. They aren't industry averages or statistics about missed calls. Use your own numbers from your call log and your records.

Is revenue at risk the same as money I'm losing?

No. It's an estimate of revenue, not profit, based only on your inputs. Some missed callers would call back or book another way, and some would never have booked.

Would an AI receptionist recover all of it?

No. Some callers want a person, and some questions need your team. A 30-Day Installation measures your baseline first and compares results at day 30, so you can judge it on your own numbers.

How does this compare with the cost of the 30-Day Installation?

The 30-Day Installation covers up to two workflows, from $5,000 one-time. If you keep it running, managed operations are from $5,000 a month on a 90-day term. Third-party software and usage are billed separately.