You just landed a client who wants an AI voice agent. Nice.
Then they ask what it will cost to run monthly and you realize you have no clean answer.
This is more common than people admit. The platforms have confusing pricing, most guides just quote the headline rate, and there is no standard for what to charge clients on top of that.
Let me break down how this actually works, and share a free tool that makes it easier. Every major platform shows a per-minute rate. And almost every one of them is incomplete.
| Platform | Advertised | Real all-in estimate |
|---|---|---|
| Vapi | $0.05/min | $0.10–$0.30/min |
| Retell AI | $0.055–$0.07/min | $0.11–$0.31/min |
| Bland AI | ~$0.09/min | Higher at low volume |
| Synthflow | $0.13–$0.20/min | Closest to actual |
The reason there is such a gap: a single call has 4 cost layers that platforms often bill separately.
Turns the caller's voice into text the model can read. Usually the cheapest part, around $0.003 to $0.02/min.
Decides what the agent actually says. The most variable cost depending on which model you use.
Generates the agent's voice. Varies by provider and voice quality.
Telephony
Actual phone carrier minutes. This is the one most people forget. Even platforms that bundle most things will often bill telephony separately.
When you add all four together, the real cost is almost always higher than what you see on the landing page.
Both work. But the choice has real consequences.
Usage-based: scales with the client and protects your margin as they grow.
Flat retainer: simpler for the client to budget around. But you need to know your break-even call volume first. That is the point where a flat fee stops covering your actual platform cost. If you do not know that number before you quote, you are just guessing.
I saw this question come up a lot with no clean tool to answer it, so I built one as part of ToolsFusion.
The AI Voice Agent Pricing Calculator takes: Platform (Vapi, Retell, Bland, Synthflow, or custom rates)
Expected monthly call volume
Average call length
Your setup hours and hourly rate
Target margin or markup
And gives you:
Recommended per-minute client rate
Flat retainer option
One-time setup fee
Break-even call volume
Everything runs in your browser. No signup, no data sent anywhere.
If you are building or selling AI voice agents, bookmark it. And if you spot anything off in the platform estimates, drop a comment. I keep them updated.
🔗 thetoolsfusion.com/calculator/ai-voice-agent-pricing-calculator