Missed call calculator for HVAC and plumbing: How much is your phone leaking?
A missed call leaves no record of the job it would have been. Plug in your own numbers and see what the silence costs each month.
Every inbound call, all lines.
After hours, lunch, Saturdays, busy line.
Not existing jobs, spam or wrong numbers.
A starting point. Change it to your own booking rate.
What a first visit is usually worth, before any replacement.
Your monthly leak
$14,625
$175,500 a year. That counts first visits only, not the replacements they lead to.
- Calls a month
- 433
- Missed
- 108
- New work missed
- 54
- Jobs lost
- 32.5
The Front Desk plan is $297 a month. At your ticket, it pays for itself after less than one recovered job a month.
Illustrative math with your inputs. For reference, ServiceTitan reports its own AI voice agents book 70% of the calls they handle, counting capacity declines. That is a vendor figure, not a measure of your missed callers (source).
How the math works
Five numbers, all yours.
Monthly leak = calls × share missed × share that's new work × booking rate × average ticket
You supply every input, which is the point. The result is illustrative, not a promise. Say half of those callers would have called back later. With the default numbers, the rest still comes to about $7,300 a month. And that counts first visits only, not the replacements they lead to.
The defaults, explained
25% missed
After hours, lunch, Saturdays and a busy line add up. It's a starting point, not an industry average. Set it to what your own call log shows.
50% new work
Not every missed call is a new job. Some are existing customers, vendors, spam or wrong numbers.
60% booking
A cautious guess for service calls. ServiceTitan reports its own AI voice agents book 70% of calls, counting capacity declines.
$450 ticket
An example first ticket for a 6 tech HVAC shop. Replace it with yours.
Why the obvious fixes fail
You've probably tried one of these.
Each one fixes part of the problem. None of them books the job and calls the lead back.
- 01Voicemail. The caller dials the next shop on Google.
- 02Hiring a CSR. Median receptionist pay is $38,010 a year before overhead (BLS, May 2025), and they still go home at 5pm.
- 03Human answering services. A person picks up, but you pay by the minute or by the call, so your busiest months cost the most. Ruby starts at $250 for 50 minutes (pricing). Smith.ai's human plan is $300 for 30 calls (pricing).
- 04DIY AI receptionists. They are cheap, and Jobber sells one as a $29 a month add-on (Jobber). That covers 30 conversations a month. Someone still has to set it up, test it and tune it, and it answers. It doesn't chase your open estimates.
- 05"My guys will call them back."They won't. They're on the next job.
About the calculator
Questions about the math.
Where do the default numbers come from?
They describe an example 6 tech HVAC shop: 25% of calls missed, half of those new work, 60% booked if answered, and a $450 first ticket. They describe an example 6 tech HVAC shop. Every number is yours to change, and the result is illustrative.
Does it include replacement jobs?
No. It counts first visits only, the service call you would have booked. If a service call turns into a furnace or water heater replacement, that is extra, and the calculator leaves it out.
What counts as new work?
A call from someone who needs a job done and isn't already mid-job with you: a new customer, or a past customer with a new problem. Calls about an existing job, vendors, spam and wrong numbers don't count.
Does it count web leads and open estimates?
No. It counts inbound calls only. Slow callbacks on paid leads and open estimates nobody chases are separate leaks, so your full leak can be larger than this number.
Know your number? Now hear the fix.
We'll call your shop three times this week and send you the report, or you can hear the agent answer right now.