Voice AI Cost Calculator
The full three-part bill — speech-to-text + LLM + text-to-speech — priced per minute, per call, and per month. LLM prices updated 2026-08-02.
- Per call
- $—
- Per month
- $—
- STT / LLM / TTS split
- —
- vs human agent ($0.75/min)
- —
Reference prices used (checked 2026-08-02)
| Layer | Service | Approx. price |
|---|---|---|
| Speech-to-text | OpenAI Whisper API | $0.006/min |
| Speech-to-text | OpenAI GPT-4o Transcribe | $0.006/min |
| Speech-to-text | Deepgram Nova | $0.0043/min |
| Speech-to-text | AssemblyAI Universal | $0.0062/min |
| Speech-to-text | Google Cloud STT | $0.016/min |
| Text-to-speech | OpenAI TTS — ~$15/1M chars ≈ $0.015/min of speech | $0.015/min |
| Text-to-speech | Google Cloud TTS (Neural) | $0.016/min |
| Text-to-speech | ElevenLabs (Creator tier) — premium quality | $0.1/min |
| Text-to-speech | Cartesia Sonic | $0.02/min |
LLM cost is computed live from our model pricing data. For the LLM layer alone across every model, use the API cost calculator.
Frequently asked questions
› How much does a voice AI agent cost per minute?
A typical stack in 2026 lands between $0.03 and $0.15 per conversation minute: speech-to-text ($0.004–$0.016/min) + LLM reasoning ($0.005–$0.08/min depending on model and verbosity) + text-to-speech ($0.015–$0.10/min depending on voice quality). Premium voices (ElevenLabs-class) can push the total past $0.15/min — at scale, TTS choice is usually the biggest lever.
› What dominates the bill: STT, LLM, or TTS?
For flagship-LLM stacks, the LLM dominates. For mini-model stacks (the sensible default for routine calls), premium TTS becomes the largest line item — often 50–70% of the total. Cheap-TTS + mini-LLM stacks get a full voice minute under $0.04.
› How do these per-minute costs compare to human agents?
A human call-center minute costs $0.50–$1.50 in most Western markets (fully loaded). Even a premium voice AI stack at $0.15/min is 3–10× cheaper, which is why voice agents are among the fastest-growing AI workloads — and why getting the per-minute math right before scaling matters.
› What hidden costs should I budget for?
Telephony (Twilio-class per-minute charges, ~$0.007–$0.02/min), silence and hold time (you often pay STT for it), interruption handling (regenerated TTS), and conversation logging/analytics. Add 20–30% to the raw stack estimate for a realistic production budget.