What a missed call actually costs a plumbing company

If you run a plumbing shop, you have seen the sales page. A big number, usually six figures, labeled "revenue you are losing to missed calls." The number is not made up out of nothing. But it is almost always built on one bad assumption, and once you fix that assumption the number gets smaller and a lot more useful.

This post walks through the math the way you would do it on the back of an invoice. You will end up with a number for your shop, not ours.

The formula, and the one assumption that matters

Lost revenue per year from missed calls is four things multiplied together:

Missed calls per week × 52 × average ticket × share that would have booked

That last term is the one the sales pages drop. They assume every missed call was a customer who would have hired you. That is not true. Some are wrong numbers. Some are vendors. Some are a homeowner who calls three shops and goes with the first one that picks up, and sometimes that would have been you and sometimes not. Some would have booked but then cancelled.

Here is the formula with reasonable defaults:

Input	Default	Where it comes from
Missed calls per week	3	Your phone system's missed-call log or carrier report
Weeks per year	52	Arithmetic
Average ticket	$800	Your own invoices (total revenue ÷ number of jobs, last 12 months)
Share that would have booked	60%	Your own booking rate on answered calls, discounted a bit

3 × 52 × $800 × 60% = $74,880 per year.

Now the inflated version. Same inputs, but assume 100% of missed calls book:

3 × 52 × $800 × 100% = $124,800 per year.

That is the number you see on most sales pages. It overstates the loss by about two thirds against the honest version. $74,880 is still a serious number for a three-truck shop. It just happens to be defensible.

Where each input comes from

Missed calls per week. This is the input people guess at, and they usually guess low. Pull it instead. Most VoIP systems (RingCentral, Dialpad, Ooma, Grasshopper) have a call log with a "missed" or "no answer" filter. If you are on a plain cell phone, the carrier's online account usually shows a call history you can export. Count calls that rang out, hit voicemail, or were abandoned in a queue. Then subtract the ones that called back and got through later. What is left is your real missed-call count.

For most owner-operated shops we talk to, the real number is between two and six a week during the season, higher during a cold snap. If you have never counted, three is a conservative default.

Average ticket. Take your total revenue from the last twelve months and divide by the number of jobs you invoiced. Do not use your biggest jobs. Do not use your minimum service fee. Use the average. For a residential service plumber this often lands between $500 and $1,200. The default of $800 is in that range.

Share that would have booked. Start with your booking rate on calls you do answer. If your CSR or your own phone converts 70% of inbound calls into a scheduled job, that is your ceiling. Then discount it, because a missed call is not identical to an answered call. The caller may have already reached another shop. We suggest shaving 10 to 15 points off your answered-call booking rate. If you book 70% of answered calls, use 55% to 60% for missed calls.

If you do not know your answered-call booking rate, 60% is a reasonable middle. Industry benchmarks vary widely and are mostly published by vendors with something to sell, so we are not going to cite one as fact. Measure your own.

Why after-hours calls skew high-ticket

Here is the part the simple formula undersells. Missed calls are not evenly distributed across the day, and neither are tickets.

Think about who calls a plumber at 9 PM or on a Sunday. Nobody calls after hours to schedule a faucet replacement for next month. They call because something is happening right now. "Water everywhere." "Sewage backing up in the basement." "No hot water and we have a newborn." "The main broke and I cannot find the shutoff."

Those calls have three things in common:

1. They are urgent, so the caller is not price-shopping. They want the first shop that answers and can come tonight or first thing tomorrow.
2. They are larger jobs. A burst supply line often becomes drywall, a water heater replacement, or a repipe conversation. A sewer backup is a camera inspection and often a line repair.
3. They carry an after-hours rate if your shop charges one.

So the after-hours missed call is both more likely to book (less shopping) and more valuable when it does. If a meaningful share of your missed calls land after 5 PM or on weekends, your real average ticket on missed calls is probably higher than your overall average.

You can model this by splitting the formula in two. Say two of your three weekly missed calls are during business hours at your normal $800 average, and one is after hours at $1,400 (a conservative emergency average with an after-hours fee). Keep the 60% booking share on both:

• Business hours: 2 × 52 × $800 × 60% = $49,920
• After hours: 1 × 52 × $1,400 × 60% = $43,680
• Total: $93,600

One after-hours call a week is worth almost as much as two daytime calls. That is why the after-hours line is the first thing to fix.

The costs the formula does not capture

The formula counts the job you did not get. It does not count a few other things that are real but harder to put a number on.

The repeat customer you never earned. A homeowner who has a good emergency experience tends to call the same plumber for the next ten years of water heaters, disposals, and fixture swaps. A missed emergency call forfeits that whole stream, not just the one job.

The review you did not get. Emergency jobs produce the most grateful customers and the most Google reviews. Reviews feed Google Local Services Ads and organic rankings, which feed future calls.

The referral. "Who did you use when your basement flooded?" is one of the most common ways plumbers get new customers.

The callback tax. When a missed call does leave a voicemail, someone has to listen to it, call back, probably hit their voicemail, and play phone tag. That is paid time, and it often ends with the customer having already booked elsewhere.

None of these belong in the headline number, because you cannot measure them cleanly. But they are the reason $74,880 is a floor, not a ceiling.

What to do about it

You have a few realistic options, and the right one depends on call volume and how you want to spend your evenings.

Answer it yourself. Free, and it works until it does not. Most owners can handle it for a while. The failure modes are predictable: you are under a sink with your hands wet, you are at your kid's game, or you are asleep. Calls at 2 AM get missed because you are a person.

Rotate the phone among techs. Common at the four-to-eight-truck size. Works if techs are disciplined about answering. Expect inconsistency in what gets booked and how it is written up, and expect the on-call tech to resent it by month three.

Hire an answering service. A human service will pick up and take a message. Most will not book into your scheduling software, and most will not triage. "Water everywhere" and "slow drain in the guest bath" get the same message slip. Costs typically run $1 to $2 per minute or in minute bundles. We compare this option in detail in AI receptionist vs. human answering service.

Hire a CSR. The best answer for a shop with the volume to justify it. A good CSR books, triages, and sells memberships. They also work about 40 hours out of the 168 in a week, so you still need an answer for the other 128.

Use an AI dispatcher. This is what Contour does. You forward your existing number (all calls, after-hours only, or only when nobody picks up within about four rings). Contour answers, asks what is happening, where, and how bad, and handles it the way a dispatcher would. For "water everywhere," that means walking the caller to the shutoff while collecting the address. For "slow drain," that means booking a normal slot. It confirms the address is in your service area, books the job into ServiceTitan or Google Calendar, and texts you within about a minute with the name, address, issue, urgency, booked time, and a link to the recording. Pricing is a flat monthly plan by answered calls, month to month, with a 30-day money-back guarantee. Details are on the pricing page.

Run your own numbers

Before you buy anything, including from us, do this:

1. Pull your missed-call count for the last four weeks from your phone system. Divide by four.
2. Pull your average ticket from your accounting or FSM software.
3. Estimate your booking share. Use your answered-call rate minus 10 to 15 points, or 60% if you do not know.
4. Multiply. Then compare the result to what any solution costs per year.

If the honest number is $20,000 a year because you miss one call a week and your tickets are small, a $600-a-month solution is a hard sell. If it is $75,000 or more, almost any serious option pays for itself many times over, and the question becomes which one fits your shop.

The ROI calculator does this arithmetic with your inputs and shows both the honest and the 100%-booking version side by side, so you can see the difference for yourself. For how we handle plumbing calls specifically, see the plumbing page and our guide to emergency triage rules for a plumbing shop.