- The core formula is missed enquiries per month, multiplied by your close rate, multiplied by your average job value.
- Most owners underestimate missed enquiries because they only count the calls they know about, not the callers who never left a voicemail.
- Roughly 80 percent of callers who reach voicemail hang up without leaving a message, and most ring a competitor next.
- Using first-job value alone understates the loss. Repeat work and referrals often double or triple the true figure.
- A week of honest tracking gives you a defensible number, which is far more useful than a vague sense that some calls slip through.
Most service business owners know they miss some enquiries. Very few have ever put a pound figure on it. That gap matters, because a vague feeling that "a few calls slip through" never justifies fixing anything, while a figure like £3,400 a month tends to move to the top of the priority list quickly.
The good news is that the calculation is simple. You need five numbers, one honest week of tracking, and about twenty minutes. This article walks through the whole thing, including the parts where owners typically fool themselves.
The five numbers you need
Before you can calculate anything, you need to gather the inputs. Each one is straightforward, but two of them are routinely underestimated, so pay attention to how you collect them.
- Your number of missed enquiries per month across every channel, including calls, web forms, emails and social messages that received a slow reply or no reply at all.
- Your close rate, meaning the percentage of enquiries that normally become paying customers when you do respond promptly.
- Your average job value, which you can find by dividing last quarter's revenue by the number of jobs completed.
- Your recovery rate, which is the percentage of missed enquiries you would realistically win back if you responded properly.
- Your customer lifetime value, if you want the full picture rather than just the first job.
The first number causes the most trouble. Your phone log shows missed calls, but it hides the true damage because most callers who hit voicemail never leave a message. Industry research consistently puts that figure at around 80 percent, so a voicemail inbox with three messages in it can represent fifteen lost callers. If you want to understand why the gap between calls and voicemails is so large, our article on why callers hang up instead of leaving voicemail covers the behaviour in detail.
To get an accurate count, track everything for one normal working week. Check your call log each evening and note every missed call from an unknown or non-customer number. Count form submissions and messages that waited more than an hour for a reply, because a slow response often loses the lead just as surely as no response. Multiply the weekly total by 4.3 to get a monthly figure.
The calculation, step by step
Once you have your inputs, the formula runs in three stages. First, multiply your missed enquiries by your close rate to find how many jobs those enquiries should have produced. Second, multiply the result by your average job value to convert jobs into revenue. Third, apply your recovery rate, because not every missed lead was winnable even with a perfect response.
A worked example makes it concrete. Suppose a plumbing firm tracks a week and finds twelve missed calls, three ignored voicemails and two web forms answered the following day, which comes to roughly 17 missed enquiries a week, or about 73 a month. The firm normally converts 40 percent of enquiries it answers promptly, and its average job is worth £320.
Seventy-three enquiries at a 40 percent close rate would have produced about 29 jobs. At £320 each, that is £9,280 in potential monthly revenue. Applying a conservative recovery rate of 50 percent, on the basis that some callers were price shoppers or would have been lost anyway, the honest figure lands at roughly £4,640 a month, or about £55,000 a year.
That firm believed it "occasionally missed a call". The tracking week and the arithmetic told a very different story. If your own missed-call count surprises you, you are in good company, and our article on how many calls the average small business misses shows how normal that surprise is.
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The calculation above uses first-job value, which understates the real loss for almost every service business. A missed caller is not just a missed £320 job. That person might have become a customer who books you twice a year for a decade and recommends you to two neighbours.
To include this, estimate how many jobs a typical customer gives you over the relationship and multiply your average job value accordingly. If the plumbing firm's typical customer books three jobs over their lifetime, the £4,640 monthly loss becomes closer to £14,000 in lifetime revenue walking out of the door each month. You do not need precision here. Even a rough lifetime multiplier shows why a missed lead costs far more than one invoice.
Be sensible with this number when you use it. The first-job figure is what you lose this quarter, and the lifetime figure is what you lose over the years ahead. Quote them separately rather than blending them, because a single inflated number is easy to dismiss.
Where the estimate can mislead you
An estimate is only useful if you trust it, so it pays to know where the model bends. Some missed calls are sales cold calls or wrong numbers, which is why the tracking week should exclude numbers you recognise as non-customers. Some enquiries would never have converted regardless of response speed. Your recovery rate handles that, and setting it at 50 percent or lower keeps the whole calculation conservative.
Close rate is the other soft spot. Owners often quote the rate they achieve on enquiries they answer quickly, then apply it to leads that sat for two days. Response speed and conversion are tightly linked, so if your follow-up is currently slow, your true close rate on those leads is lower than you think. The fix is the same in both directions, which is to respond faster and follow up consistently.
What to do with the number
Once you have a figure, compare it against the cost of fixing the leak. If you are losing £4,000 a month, then a call answering rota, a missed-call text-back system, or automated follow-up sequences all pay for themselves many times over. Most owners find that the maths makes the decision for them.
Start with the channel that leaks the most. For most trades and local services that means the phone, because calls arrive while you are on a job and cannot answer. A system that texts every missed caller within seconds recovers a large share of the leads that would otherwise ring your competitor, and it works without you touching your phone. EveryCatch builds exactly this for service businesses, but even if you assemble something yourself, the principle stands. Measure the leak first, then plug the biggest hole, then measure again next month to prove the improvement.
From the EveryCatch team
EveryCatch helps service businesses catch and convert every enquiry with instant missed-call text-back, automated follow-up and simple pipeline tracking. We write these guides to answer the questions owners actually search for, honestly and without the sales pitch.
