About CallMath
An independent calculator for one question small businesses keep asking: what will an AI receptionist or answering service actually cost at my call volume?
Who built it
CallMath is built by Mahir Patel, an electrical-engineering student at the University of Illinois Urbana-Champaign who spent fall 2026 researching this market.
Why it exists
AI receptionist vendors price in different units: minutes, calls, conversations, unique callers or a flat rate, each with its own overage rule. That makes sticker prices impossible to compare, and we found no neutral page that normalizes them. CallMath takes the number an owner knows (calls a month), converts it into each vendor's unit and shows the arithmetic. 13 vendors are ranked today; the rest are listed with the reason they aren't.
How it stays neutral
- Ranking uses only the computed monthly cost and how well a plan fits what you asked for. The methodology shows every formula.
- Every price comes from the vendor's own website, with the date we read it. Unclear or unpublished prices are marked "not verified" and never ranked.
- No vendor pays for placement. We have no affiliate agreements today. If that changes, each program will be listed on the disclosure page, and it still won't change the order.
- No invented reviews, ratings or pros and cons. Vendor pages state only what the vendor's own pages say, and list what they leave out.
A conflict of interest, disclosed
Ringlatch is not listed: The founder's own product (currently paused). Not listed, to avoid a conflict of interest. CallMath's analytics and link redirects run on a small service the founder operates at pulse.ringlatch.workers.dev, a web address named after that paused project; it carries no Ringlatch product or advertising.
Contact
Corrections, vendor suggestions and questions are welcome through the contact form.