What does a missed call really cost you? The method to calculate it

Before talking money, let’s frame the stakes. You often hear that “nobody calls anymore.” The figures from ARCEP tell a different story: in 2024, voice traffic from French businesses accounted for 31.2 billion minutes, or 14% of all voice usage in the country.

This usage is declining slowly (−3% over the year, part of a trend spanning more than ten years). But 31 billion minutes is a volume that translates, every single day, into requests for quotes, appointments, and information. For a large share of professionals, the phone remains the primary entry channel for a new customer.

Every call that goes unanswered is therefore a potential transaction that quietly evaporates. The goal of this article: turn that silence into a figure you can write down in black and white.

The cost of a missed call is no mystery. It follows from four numbers you already know, or that you can obtain in a few minutes:

• Call volume — how many inbound calls do you receive over a given period (monthly is the most convenient)?
• Missed-call rate — what share of those calls goes without a human answer (ringing into the void, voicemail, busy line)?
• Conversion rate — among the calls you do answer, what proportion becomes a customer (or a confirmed appointment)?
• Customer value — how much does a customer won by phone bring you on average (average order value, or better still: value over the entire lifetime of the relationship)?

You simply chain the four variables together. Your monthly lost revenue reads as follows:

Volume × Missed-call rate × Conversion rate × Customer value = monthly lost revenue.

Proceed in this order. First, apply your missed-call rate to your volume: you get the number of unanswered calls for the month. Then apply your usual conversion rate to that number: that’s the number of customers those calls would likely have brought you. Finally, multiply by the average value of a customer: you now have your monthly lost revenue, which you simply multiply by twelve for the annual estimate.

The underlying logic is what counts: the calls you miss would convert at the same rate as those you handle. You’re not losing “a few calls,” you’re losing a proportional fraction of your inbound revenue, month after month. It’s this perspective that almost always surprises people with its scale — once you’ve plugged in your own numbers.

The mistake would be to estimate these variables by gut feeling. Each one can be measured.

Volume and missed-call rate appear in the statistics from your carrier or your phone system. The majority of business lines are now VoIP (68% of professional lines according to ARCEP), and these systems log calls received, answered, and abandoned. Ask for the history over three months to smooth out the variations.

The conversion rate can be reconstructed from your calendar or your management software: how many inbound phone requests led to a sale or a kept appointment? If you’re not tracking it yet, start with a week of manual observation.

Customer value is the most strategic variable. Don’t limit yourself to the first sale: a customer captured today comes back, refers others, renews. Think in terms of the total value of the relationship, not the initial transaction, otherwise you’ll greatly underestimate the cost of every lost call.

The calculation above captures direct lost revenue. But a missed call carries a hidden cost, harder to quantify and yet very real.

First, the caller who can’t reach you doesn’t disappear: they have a need, and they’ll resolve it elsewhere. You’re not only paying for the lost sale, you may be funding a competitor’s. There is no reliable public statistic on the exact share of these callers who turn elsewhere; but common sense is enough to understand that an urgent need won’t wait.

Second, there’s perception. An unanswered call, or a voicemail, sends a signal of unavailability from the very first contact. This matters all the more as expectations evolve: according to the 2024 Customer Service Observatory (BVA Xsight), 89% of French people believe AI will be present in customer service within less than ten years — even though only one in three actually wants it. In other words, your customers expect to be taken care of, while remaining demanding about the quality of that care.

These dimensions don’t fit into a multiplication. But once your direct lost revenue is established, keep in mind that it’s a floor, not a ceiling.

When you have your monthly figure, you hold the only benchmark worth having to make a decision. Any solution designed to recover these calls — hiring, outsourcing, a voice agent — should be judged by comparing it to that lost revenue. If the cost of the solution is lower than the revenue it recovers, the trade-off is settled.

Tinos sits precisely on this line: it’s a voice agent that answers on your behalf 24/7, qualifies the call, books the appointment and notifies you by SMS or email, then records it in the tool you already use. Hosted in the European Union and GDPR-compliant, the agent announces itself as an AI at the very start of the call and runs on a monthly subscription, with no per-minute billing. The idea isn’t to replace the human relationship, but to make sure that no call — and therefore none of the customers you’ve just put a number on — ever falls into the void again.

• ARCEP — Observatory of electronic communications markets in France 2024
• BVA Xsight — Customer Service Observatory 2024