In short: The ROI of an AI voice agent is the benefit minus the cost, divided by the cost. The benefit comes from three sources: working time that is freed up, enquiries that would otherwise be lost, and costs you avoid, such as an extra hire or an answering service. In our worked examples, saved working time alone does not always cover the agent. The calculation becomes clearly positive when the agent answers calls nobody answers today, or replaces a hire you would otherwise need.
We rewrote this article in October 2026. The previous version promised complete availability and a positive ROI after the first quarter, with no calculation and no source. Both are gone. Instead we show the calculation with stated assumptions that you can replace with your own numbers.
The ROI formula for AI voice agents
ROI = (benefit − cost) ÷ cost × 100
On the cost side there are three items:
- The provider's plan. At EchoCall €75 for 250 minutes, €150 for 500, €450 for 1,500 and €1,500 for 5,000 minutes a month, which is €0.30 per minute, with no setup fee. [5]
- Phone number and telephony. At EchoCall they are not included in the plan price.
- Your own time. Adding knowledge, connecting the calendar, setting up transfers, testing and improving later. Most calculations forget these hours.
On the benefit side there are also three items:
- Saved working time. Calls the agent resolves completely are calls your team does not have to take.
- Additional contribution margin. Enquiries outside opening hours or at peak times that are lost today. Calculate with the contribution margin here, not with revenue.
- Avoided costs. A part-time post you do not need to create, or an answering service you cancel.
What an hour on the phone costs
For saved working time you need an hourly rate. A call centre agent in Germany earns a median of €2,420 gross a month. [3] Employer social security contributions add roughly 21 percent. [4] Together that is about €2,930 a month.
How many of those hours are actually worked depends on holidays, sickness, breaks and training. We assume 140 productive hours a month. That gives about €21 per hour, or about €0.35 per minute of working time. Workspace, software and team management are not included.
This figure is close to the €0.30 per minute an EchoCall agent costs. That is the most important point of this article: an AI voice agent saves little per minute if it only takes over calls your team would have handled anyway in its paid time. The ROI comes from elsewhere.
Worked example A: relieving customer service
| Assumption | Value |
|---|---|
| calls per month | 600 of 2.5 minutes, 1,500 minutes |
| resolved completely by the agent | 50 %, so 300 calls |
| wrap-up time your team saves per call | 1 minute |
| saved working time | 300 × 3.5 minutes = 17.5 hours |
| value of that time | 17.5 × €21 = about €370 |
| cost of the agent | €450 for 1,500 minutes, plus telephony |
Result: about €370 of benefit against €450 of cost. On saved working time alone, the agent does not pay for itself in this scenario. It is still worthwhile if the freed 17.5 hours go into work that earns money, or if the relief means you avoid a hire. Then you are at example C.
Worked example B: calls that are lost today
| Assumption | Value |
|---|---|
| calls out of hours and at peak times | 40 a month of 2.5 minutes each |
| of which new enquiries | 50 %, so 20 |
| of which lost without the agent | 50 %, so 10 |
| close rate | 30 %, so 3 jobs |
| job value | €400, €1,200 revenue in total |
| contribution margin | 40 %, so €480 |
| cost of the agent | €75 for 250 minutes, plus telephony |
Result: ROI = (€480 − €75) ÷ €75 × 100 = 540 percent, before telephony costs. Here the agent pays off because it answers calls nobody else answers. How to count the missed calls in your business is explained in Missed Calls Cost Revenue.
Worked example C: the part-time post you do not create
| Assumption | Value |
|---|---|
| planned part-time post for the phone | 20 hours a week |
| cost of the part-time post | about half of €2,930, so about €1,465 |
| call minutes the agent takes over | 1,500 a month |
| cost of the agent | €450, plus telephony |
Result: ROI = (€1,465 − €450) ÷ €450 × 100 = about 226 percent. The caveat belongs with it: a part-time employee also does work beyond the phone, greets visitors, sorts post and deals with complaints. The agent replaces the phone part of the job, not the job.
Payback: when the agent has paid for itself
The payback period is the time until the benefit has covered the one-off costs. EchoCall charges no setup fee, so the one-off cost is mainly your own time. If we assume eight hours for setup and testing, at €21 an hour that is about €170.
- Example B: a surplus of €405 a month. Setup is paid for in the first month.
- Example C: a surplus of about €1,015 a month. Also within the first month.
- Example A: on working time alone the agent does not pay back. It needs a second benefit.
These numbers are only as good as the assumptions. Change the close rate in example B from 30 to 10 percent and one job with €160 of contribution margin remains. That still covers the €75, but more narrowly.
Is there a cost savings benchmark for AI voice agents?
We know of no independent, cross-industry benchmark for the savings from AI voice agents. What exists are analyst predictions and published prices you can compare yourself.
Predictions. Gartner expects that by 2029 agentic AI will autonomously resolve 80 percent of common customer service issues without human intervention, leading to a 30 percent reduction in operational costs. [1] Back in 2022 Gartner wrote that labour can represent up to 95 percent of contact centre costs, and projected that one in ten agent interactions would be automated by 2026. [2] These are forecasts for large contact centres, not measurements in your business.
Price comparison. According to a market overview by the outsourcing provider yoummday, a German-language outsourced call centre costs €0.50 to €1.20 per inbound talk minute. [6] An AI voice agent at EchoCall costs €0.30 per minute. Against outsourcing the saving per minute is clear. Against your own team, as shown above, it is rather small.
Read vendor case studies with percentage savings with one question in mind: was the same thing measured before and after? Often there is no statement of which calls were counted and which costs are in the calculation.
What drags the ROI down
- Thin knowledge. An agent that only knows the opening hours transfers almost everything and resolves little.
- No transfer. Callers who get stuck and cannot reach a person hang up and do not call again. In a Gartner survey of 3,566 customers, 87 percent said that a company using generative AI in customer service must offer a way to reach a human. [7]
- Complex calls. Advice that needs judgement, complaints and negotiations stay with people. A high share of such calls lowers the rate of calls resolved completely.
- Low volume without gaps. If your team answers every call and has time, there is little to gain.
- No maintenance. New services, prices and opening hours have to go into the knowledge base, or quality drops.
Which voice bot has the best ROI?
That depends less on the product than on the pricing model and your own effort. Developer platforms are cheaper per minute but need engineering time, which many ROI calculations leave out. Ready-made products cost more per minute but are quicker to set up and your team can maintain them. List prices of the main providers and a worked example for 500 minutes are in AI Phone Agents Compared 2026.
Build your own ROI calculator in a spreadsheet
You do not need a vendor's calculator. A spreadsheet with these rows is enough:
- calls per month and average duration
- share the agent should resolve completely
- your hourly rate for time on the phone
- calls out of hours and at peak times
- share of new enquiries, loss rate without the agent, close rate, job value, contribution margin
- avoided costs: a post, an answering service, overtime
- plan price, phone number and telephony
- your hours for setup and maintenance
Fill it in first with cautious values. After four weeks of live use, replace the assumptions with what you measured: how many calls the agent answered, how many it resolved completely, how many appointments were booked and how many calls came outside opening hours.
Check the ROI in a trial
The simplest way to test the assumptions is with real calls. At EchoCall you get 30 voice minutes and 30 chat conversations for 14 days, and the credit card is verified with €1. The live demo gives a first impression without signing up: it builds an agent from your website in about 20 seconds that you can call in the browser.
Frequently asked questions
How do I calculate the ROI of an AI voice agent?
ROI = (benefit − cost) ÷ cost × 100. The benefit is made up of saved working time, additional contribution margin from enquiries that would otherwise be lost, and avoided costs. The costs are the plan, phone number, telephony and your time for setup and maintenance.
Is there a cost savings benchmark for AI voice agents?
We know of no independent, cross-industry benchmark. Gartner predicts that by 2029 agentic AI will resolve 80 percent of common service issues and cut operational costs by 30 percent. That is a forecast. For your business a comparison of per-minute prices says more: outsourcing costs €0.50 to €1.20 per minute according to yoummday, EchoCall €0.30.
When does an AI voice agent pay for itself?
If it answers calls that are lost today or replaces a hire, often in the first month. If it only takes over calls your team would have handled anyway, it usually does not pay back through working time alone.
Is an AI voice agent cheaper than an employee?
Per minute, hardly. A minute of working time at a median wage plus employer contributions costs about €0.35, an EchoCall agent €0.30. The difference is availability: the agent also answers in the evening, at weekends and at peak times.
What is the ROI of using AI voice agents for support?
It depends on how many calls the agent resolves completely and what happens to the time it frees. In our example A, with 600 support calls a month and half of them resolved, the saved working time is worth about €370 against €450 of cost. Support pays off when the agent also covers hours your team cannot, or when it saves you a hire.
Which voice bot has the best ROI?
The one whose pricing model fits your volume and that your team can maintain itself. A low per-minute price brings little if you have to add engineering time. Compare using your own minutes, not list prices alone.
Sources
- Gartner, press release of 5 March 2025, agentic AI prediction for 2029: gartner.com
- Gartner, press release of 31 August 2022, conversational AI and contact centre labour costs: gartner.com
- brutto-netto-gehaltsrechner.de, call centre agent salary, median €2,420 (in German): brutto-netto-gehaltsrechner.de
- lohnklar.de, employer social security contributions 2026 (in German): lohnklar.de
- EchoCall pricing: echocall.de/en/pricing
- yoummday, Call Center Costs, market ranges for German-language providers: yoummday.com
- Gartner, survey of 3,566 customers, press release of 4 August 2026, quoted by IT-Online: it-online.co.za
All links were checked on 6 October 2026. Third-party prices can change.
