As a worked example, 1,000 five-minute inbound AI calls on Twilio cost $65.65 a month, made up of $42.50 in minutes, $22.00 for Media Streams and $1.15 for a local number. Made outbound, the same calls cost $93.15. Dograh, the open-source AI voice agent platform we build, adds the platform line. You can self-host it or use Dograh Cloud.
Key Takeaways
- Multiply billed minutes, not spoken minutes, by the minute and stream rates.
- Models sit on their own line and usually outweigh the phone line.
- Twilio recording only adds cost if you switch it on in Twilio.
This post is part of our guide to Twilio pricing, which prices every line of one 5-minute AI call. Here that call becomes a calculator: the formula with each input, 1,000 inbound and 1,000 outbound calls, the inputs that move the total, then the platform and model lines.
The formula, one input at a time
A Twilio bill for AI calls is a few multiplications you can do in any spreadsheet. Here is the whole formula, with the platform and models added at the end:
calls x billed minutes per call x (minute rate + stream rate) + numbers + recording, if used + platform fee + models
Each input has a public value. The minute rate depends on direction and number type. On Twilio, receiving a call on a local number costs $0.0085 a minute, on a toll-free number $0.0220, and making a call to US and Canada numbers $0.0140. The stream rate is Media Streams at $0.0044 a minute, which an AI agent pays to receive the call's audio. A local number is $1.15 a month and a toll-free number $2.15.
Billed minutes are the input people get wrong most often. Twilio rounds each call up to the next full minute, so use the rounded length, not the average talk time. The examples below use 1,000 calls at exactly 5 billed minutes, which is 5,000 minutes a month on one local number.
1,000 inbound calls, worked through
The first worked example is an inbound line, such as a front desk or a support number, answering 1,000 calls in a month. Every call comes in on one local number and runs 5 billed minutes.
| Input | Working | Cost |
|---|---|---|
| Inbound minutes, local number | 5,000 x $0.0085 | $42.50 |
| Media Streams | 5,000 x $0.0044 | $22.00 |
| One local number | 1 x $1.15 | $1.15 |
| Twilio total | $65.65 |
That is about 6.6 cents a call from Twilio. Media Streams is a third of the total, which is the line a minutes-only estimate misses. If the same line ran on a toll-free number, the minutes would become 5,000 x $0.0220, or $110.00, and the number $2.15, for $134.15 in all.
1,000 outbound calls, worked through
The second worked example is an outbound campaign, such as appointment reminders, with 1,000 connected calls of 5 billed minutes each. The agent dials out from the same local number.
| Input | Working | Cost |
|---|---|---|
| Outbound minutes, US and Canada | 5,000 x $0.0140 | $70.00 |
| Media Streams | 5,000 x $0.0044 | $22.00 |
| One local number | 1 x $1.15 | $1.15 |
| Twilio total | $93.15 |
Outbound costs more because of the higher minute rate, and the stream line stays the same $22.00. Calls that fail or come back busy are not billed, so count connected calls here, not dial attempts.
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Inputs that move the total
Four inputs change the result more than people expect, and rounding is the largest. If your calls average 4 minutes 10 seconds, each one bills as 5 minutes, so 1,000 calls bill 5,000 minutes, not 4,167. That is 833 minutes nobody spoke, worth about $10.75 on the inbound example.
Recording only counts if you turn it on in Twilio. It would add 5,000 x $0.0025, or $12.50, plus $2.50 a month in recording storage for every month you keep the recordings. Dograh's Twilio connection doesn't ask Twilio to record, and Dograh keeps its own recording and transcript of each call, so leave this line at zero unless your Twilio account records as well.
Transfers add a second leg. Each call handed to a person adds outbound minutes at $0.0140 to that person's phone, plus conference minutes starting at $0.0018 per participant per minute. Add a line for the share of calls you expect to transfer and how long the handover runs.
Twilio's own answering machine detection, at $0.0075 a call, can stay out of the formula, since Dograh has its own voicemail handling. If your callers are outside the US, Twilio's Voice Pricing API returns the rates for each country.
Add the platform and model lines
The Twilio total is only the phone line, and two more lines finish the bill. The platform line depends on how you run the agent. Self-hosted Dograh has no per-minute platform fee, but servers, model keys and phone minutes still cost money. Dograh Cloud charges a 1¢-a-minute platform fee. That is $50.00 for the 5,000 minutes in both examples.
The model line is speech-to-text, the language model and the voice, and it depends entirely on which providers you choose. With your own keys, each one bills you at its published rate, so put those rates into the formula as their own line. Our breakdown of what an AI voice agent costs per minute gives typical per-minute figures, and our guide to LLM API pricing for voice agents prices the language model by token.
The voice is often the easiest model line to shrink. Pre-recorded audio plays recorded clips for the lines your agent repeats on every call and generates speech only for the rest, so fewer minutes reach your voice provider.
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Glossary
- Billed minutes
- Call length after Twilio's rounding. Each call leg is rounded up to the next full minute, so billed minutes are always at least the spoken minutes, and the gap grows with short calls.
- Media Streams
- Twilio's feature that sends a call's live audio to your agent and plays back its replies, at $0.0044 a minute. On AI calls it is a line of its own, beside the minute rate.
- Recording storage
- Twilio's monthly charge for keeping a recording, $0.0005 per recorded minute per month. It repeats every month you keep the file, so it grows over time even with no new calls.
- Pricing API
- Twilio's API that returns voice prices for a country or a phone number. It lets you fill the formula's minute rates for callers outside the US without looking up each country's rate by hand.
