Investor brief · Nov 2026

The cost of teaching one student

Our AI teacher writes each lesson and draws it on a board, then explains it aloud in Sinhala, Tamil or English. We priced this page from the token counts of 211 production AI calls made in October and November 2026, at the model prices OpenRouter lists today. Pick a student below and the numbers update.

Period

Subjects

A/L students take 3 subjects and O/L students take up to 9.

Study level

Call size

Currency

Plan

Out of credits

AI price

The student pays

It costs us

Gross profit

Gross margin

Cost to serve, line by line

Low, medium and high study

As they add subjects

If AI prices change

One credit

Students spend credits on AI work, and the bars compare a credit's price with our cost to deliver it.

A free sign-up

We give each new student 100 credits once, enough for a first lesson taught on the board.

Free students read shared lessons that we write once per topic and language, so later sign-ups on a topic we've already written cost us much less.

The plans

Plan credits renew monthly, while top-up credits cost more each but don't expire.

Study levels per subject

Monthly activity for one subject, which we repeat for each subject a student takes.

Price and cost per action

Sources and assumptions

Token counts come from production. We pulled OpenRouter's record of 211 AI calls from the production database and priced each action's average tokens at $2 per million input tokens and $10 per million output tokens, our model's discounted price today. Those calls used no reasoning tokens and almost no cache, and because the $4 / $20 full price doubles each rate, full price costs exactly twice what we pay today.
The premium model needs more tokens for the same text. It lists at the same $4 / $20 as our model's full price, but when we sent real lessons and boards to both, it used 1.38 times as many tokens for Sinhala, 1.14 for English and 1.98 for Tamil. Across our lessons (69% Sinhala, 25% English and 6% Tamil) that averages 1.36, and we assume it writes lessons of the same length.
The teacher's voice uses the same speech model at every AI price on this page. At $0.50 per million text tokens in and $9 per million audio tokens out, 71 production calls came to $0.0202 per 1,000 characters, and a voiced board averages 3,170 characters, about 4.5 minutes of speech including answers to questions.
Each notebook page gets its own board, and a lesson averages 11 pages.
Unbilled AI work adds 5% for images, safety checks, refunded failures, pre-built quizzes and voice we regenerate after its 30-day cache expires.
OpenRouter charges 5.5% when we buy AI credits.
Hosting comes to about LKR 135 per student a month. Cloudflare Workers, Neon Postgres, R2 storage and email cost about $35 a month in fixed fees, which we spread over 100 paying students, and storage grows by about 7 MB per student a month.
Card payments cost 3.3% on PayHere's Lite plan, falling to 2.99% on Plus or 2.49% on EDU as volume grows.
A 10% safety buffer sits on top of the other costs, for price changes and heavier use.
We convert at LKR 337 per US$, the bank selling rate on 5 November 2026 (spot was LKR 332.6), because AI and hosting bill in dollars.
Credits cap our cost because a student can only use the credits they've paid for. A student who waits for renewal pauses until next month, and one who buys top-ups pays top-up prices for the extra.
Shared lessons make these figures conservative. Starter and Free students read lessons we write once per topic and language, but this page counts each lesson at full cost.
The page leaves out Sri Lankan VAT on foreign digital services (from July 2026), student acquisition, salaries and content creation.
The year view bills 12 months of the same study pattern.