What would this cost you?
Most voice-agent cost estimates compare vendors -- one TTS price against another, one LLM against another. This one compares architectures, holding the vendor stack fixed.
A naive build resends the whole growing conversation to the LLM on every turn and re-synthesises every reply from scratch, so its per-call cost climbs with call length. VARTA keeps a bounded, non-accumulating prompt per turn and replays cached audio for repeated phrasing instead of regenerating it, so a longer call does not automatically mean a proportionally more expensive one. Set your own call volume, call length, cache-hit rate and language below, pick a baseline stack to compare against, and see both totals -- and every line item behind them.
Indic India stack (naive build)
₹18,953 / month
VARTA, same stack's vendor rates
₹10,126 / month
Estimated difference: ₹8,827 a month (47% lower under VARTA's architecture).
Where the difference comes from
The total above is an assertion; this is the evidence — cost by component, monthly, under each architecture.
| Component | Indic India stack | VARTA |
|---|---|---|
| Text-to-speech | ₹43 | ₹19 |
| Language model | ₹97 | ₹5 |
| Speech-to-text | ₹18 | ₹23 |
| Telephony | ₹36 | ₹42 |
| Media platform | ₹32 | ₹32 |
This shows your own estimated monthly cost under two different architectures, built from public vendor list prices — never a VARTA rate card, and never a "from ₹X" price. VARTA carries no time-based unit rate, here or anywhere else: a rate that scaled with call duration would hide the effect of caching, which is exactly what this comparison exists to show.
Assumptions behind this estimate
- Exchange rate
- ₹84.00 = $1.00 (pinned figure, mirrored from the source cost model on 2026-08-27 — not independently re-checked against a live FX feed)
- Pace of a call
- About one agent-customer exchange every twenty seconds (6 conversation turns across a 60-second span of call time) — a pacing assumption, not a measurement of real call logs.
- Agent turn length
- ~120 characters of spoken reply — roughly one short sentence, the length of a typical confirmation or answer.
- Customer turn length
- ~15 tokens — a short reply such as a yes/no, a date, or a name.
Two modelling choices in this calculator make VARTA look cheaper than a real call may be, so the saving shown here is closer to a ceiling than a guarantee. First, we model VARTA’s context on each answered turn as a fixed 340-token prompt — the measured size of VARTA's own routing prompt, used as a lower bound, not a measurement of everything a live call's context can hold. Second, we charge exactly one LLM call for every turn VARTA has to think about, though a real turn can involve more than one call (for example, a classification step and a routing step). Neither assumption is applied to the other architecture, so both push the reported saving up, not down.
On the rates themselves: These figures are recorded as vendor list prices in the source cost model and have not been independently re-verified here — treat each as a starting point, not a confirmed-current rate. Each provider row is dated (asOf) to when it was last checked against its sourceUrl — some rows are older than others. List prices are used on purpose: a vendor offering a negotiated discount would only widen the savings gap this calculator shows, so this comparison is conservative rather than inflated. Refresh each rate against its source before citing it in a published case study.
Sources
- Indic India stack — text-to-speech vendor (checked 14 May 2026)
- Indic India stack — language model (checked 14 May 2026)
- Indic India stack — speech-to-text vendor (checked 15 Jul 2026)
- Indic India stack — telephony carrier (checked 14 May 2026)
- VARTA's speech-to-text vendor (fixed, not part of the compared stack) (checked 15 Jul 2026)
- VARTA's telephony carrier (fixed, not part of the compared stack) (checked 14 May 2026)
Every figure above is built from public vendor list prices and the same per-unit rate tables and cost helpers that price real VARTA calls in production, run through a documented set of modelling assumptions and checked against goldens generated by that real code. Read exactly how it works -- including where this calculator's code stops being the same code that prices a live call, and the two assumptions that run in VARTA's favour -- on the methodology page.
Want this priced for your own workflows?
This estimate uses a generic call shape. Talk to us about a build sized to your actual call volume, languages, and existing telephony and vendor contracts.
Talk to sales