AI voice agent cost calculator

How much do AI voice agents cost?

Cost depends on the models, phone rates, call length, and usage. With this calculator's default models and assumptions, a 5-minute call costs about $0.1738 in usage, or $0.0348 per minute. At 500 calls per month, that is approximately $86.90 before platform fees and other costs. This number is an estimate for one configuration.

Read the worked example, or change the inputs below.

Estimates use prices from the open Hail costs dataset, cached for 24 hours. Copy the page URL to share this configuration.

Worked example: 500 calls per month

This example uses 5-minute calls, totaling 2,500 minutes per month. The example always uses the default models. It does not change when you change the calculator inputs.

• Telephony: $0.014 per minute (an assumption that you can edit).
• Speech-to-text: Deepgram Nova-3 Monolingual, $0.0048 per audio minute.
• Text-to-speech: ElevenLabs Eleven Flash v2.5, $40.00 per million characters.
• Language model: OpenAI GPT-4o mini, $0.15 input and $0.60 output per million tokens.

Totals use unrounded values. Model rates come from the Hail costs dataset, fetched with a 24-hour cache.

How the estimate works

The estimate charges telephony and speech-to-text for the full call duration. It charges text-to-speech for the characters that the agent speaks. The estimate assumes 150 words per minute of conversation, and the agent speaks 50% of the time, at 5 characters per word. The LLM cost is per token. The estimate assumes 4 turns per minute. Each turn resends a 1000-token system prompt and the transcript so far, at 1.33 tokens per word. All model prices come from the open Hail costs dataset. Monthly usage cost is the estimated per-call cost multiplied by calls per month. A longer call also increases the transcript that each turn resends. Under these assumptions, a call of double length can cost more than double in LLM usage.

What costs are missing from the estimate?

Add any platform or orchestration fees, phone-number rental, hosting, recording and storage, monitoring, integrations, setup work, support, and taxes that apply to your deployment. The calculator does not model minimum charges, billing increments, subscription allowances, or volume discounts.

When you compare a managed service, check which of these items its quoted rate includes before you add separate model costs. For Hail's own charges, see pricing.

Is there a free AI voice agent available?

This calculator does not run a voice agent. For a free agent offer, check whether it covers phone calls, model usage, and hosting. Check how many minutes are included and what happens when credits expire. A free software license alone does not cover those services.

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