HVAC missed-call revenue calculator
Put your own call volume in and see what unanswered calls plausibly cost you per month and per year. No email required, no gate — the numbers update as you type, and the formula is published below so you can check the arithmetic yourself.
Your HVAC call numbers
Adjust the inputs to estimate missed calls per month, lost repair revenue, replacement revenue at risk, and estimated yearly leakage.
Estimates only, not guarantees. Assumes missed callers would book at the same rate as answered calls, and that a small share (~5%) of lost service calls represented a system-replacement opportunity.
How this calculator works
Most missed-call calculators hide their assumptions, which makes the output impossible to argue with — and impossible to trust. Here is the entire model in four lines:
Missed calls per month = calls per week × missed % × 4.33
Lost booked jobs = missed calls per month × booking rate
Lost repair revenue = lost booked jobs × average repair ticket
Replacement revenue at risk = lost booked jobs × 5% × average replacement value
Yearly leakage is the sum of the last two lines, multiplied by twelve.
The 4.33 converts weeks to months. The 5% is the one figure we impose rather than ask you for: it assumes one in twenty missed service calls was actually someone whose system was at the end of its life and who would have ended up buying a replacement. If that feels high or low for your market, treat the replacement line as a sensitivity check rather than a hard number.
Where to find each input
The calculator is only as honest as what you feed it. These are the specific places to look rather than guessing:
| Input | Where the real number lives | Common mistake |
|---|---|---|
| Inbound calls per week | Your call tracking platform, or the call log in ServiceTitan, Housecall Pro, or Jobber. Use a normal week, not a heat wave. | Counting outbound and internal calls in the total. |
| Missed-call percentage | Unanswered + abandoned + voicemail, divided by total inbound. Most phone systems report this directly. | Only counting rings that hit voicemail, and ignoring callers who hung up while on hold. |
| Average repair ticket | Total repair revenue ÷ number of repair jobs, over the last 90 days. | Using the price of a service call instead of the completed ticket. |
| Booking rate | Booked jobs ÷ answered inbound service calls. Your CSR scorecard, if you keep one. | Using a lead-to-close rate from marketing instead of a call-to-booking rate. |
| Replacement opportunity value | Average install/changeout revenue over the last year. | Using the sticker price of the equipment rather than the installed job value. |
Why this estimate is deliberately conservative
The model assumes a missed caller is worth exactly as much as an answered one, and no more. In practice there are three effects it ignores, all of which push the real number higher:
- Acquisition cost is already sunk. If the call came from a paid ad, a truck wrap, or a Google Business Profile listing, you already paid to make the phone ring. A missed call wastes the marketing spend as well as the job.
- Lifetime value, not ticket value. A first-time repair customer who becomes a maintenance-plan member is worth several years of revenue, not one ticket. The calculator only counts the first job.
- Emergency calls skew high. After-hours no-cool and no-heat calls tend to convert better and carry larger tickets than the daytime average, and they are also the calls most likely to be missed.
It also ignores effects that push the number down — some callers ring you twice and get through the second time, and some were never going to buy. That is the point of keeping the model simple: it gives you a defensible floor rather than a marketing number.
What to do with the number
A yearly leakage figure is only useful if it changes a decision. The three decisions it usually informs:
- Whether the gap is a staffing problem or a coverage problem. If most of your missed calls land between 8am and 5pm, you have a capacity problem in the office and another CSR may be the cheaper fix. If they cluster after hours and at weekends, no amount of daytime hiring closes it.
- What you can justify spending. Compare the monthly leakage figure against the monthly cost of coverage — whether that is overtime, an answering service, or an AI answering service. If the leak is smaller than the fix, do nothing.
- Which calls to cover first. Almost nobody should cover every call on day one. Most HVAC companies start with after-hours and overflow only, which is where the leakage concentrates.
For the industry benchmarks behind these figures — missed-call rates, callback behaviour, and what the commonly quoted statistics actually come from — see our HVAC missed-call research page, which labels each figure by source quality.
Questions about the calculator
Do I have to give you my email to see the result?
No. The calculator runs entirely in your browser, the results appear as you type, and nothing you enter is sent to us or stored anywhere. There is no gate and no export step.
Is this a guarantee of recovered revenue?
No, and any vendor who tells you otherwise is selling. This is a sizing estimate built on your own inputs and a published formula. It tells you roughly how large the opportunity is, not how much of it any system will recover.
What missed-call percentage should I use if I do not know mine?
Rather than guess, pull one week of call logs from your phone system — almost all of them report answered versus unanswered. If you genuinely cannot get the data, run the calculator twice at 10% and 25% to see the range, then treat the gap between them as the reason to go measure it properly.
Does this apply to plumbing and electrical too?
The arithmetic does, but the defaults do not. The pre-filled ticket and replacement values are HVAC-shaped. If you run a plumbing or electrical shop, replace all five inputs with your own figures and the model still holds.
Check the estimate against your real call logs
The calculator gives you a modelled number. A missed-call audit gives you the actual one: we go through your call tracking and dispatch records, separate genuinely missed revenue calls from spam, wrong numbers, and repeat dials, and show you when in the week the leak actually happens.