What’s on the Tokens & Cost poster
A definition and 6 facts worth remembering.
Providers bill by token, usually at different rates for input and output. A token is roughly four characters of English, so a page of text is about 500 tokens.
- ~750 words ≈ 1,000 tokens in English.
- Output tokens usually cost several times input tokens.
- The whole conversation is resent on every turn.
- A long system prompt is paid for on every request.
- Caching can cut the cost of a repeated prefix substantially.
- Other languages tokenise less efficiently than English.
- 1,000 tokens — ~750 words
- 1 token — ~4 chars
- A page — ~500 tokens
- A 2,000-token system prompt over 10,000 calls is 20 million input tokens, before any…
Trim the system prompt before optimising anything else. It is the one cost multiplied by every request you serve.
Questions about the Tokens & Cost poster
- What’s on the Tokens & Cost poster?
- A definition and 6 facts worth remembering. Providers bill by token, usually at different rates for input and output. A token is roughly four characters of English, so a page of text is about 500 tokens. ~750 words ≈ 1,000 tokens in English.; Output tokens usually cost several times input tokens.; The whole conversation is resent on every turn.; A long system prompt is paid for on every request.; Caching can cut the cost of a repeated prefix substantially.; Other languages tokenise less efficiently than English.; 1,000 tokens — ~750 words; 1 token — ~4 chars; A page — ~500 tokens; A 2,000-token system prompt over 10,000 calls is 20 million input tokens, before any…. Trim the system prompt before optimising anything else. It is the one cost multiplied by every request you serve.
- Who is the Tokens & Cost poster for?
- Tokens & Cost belongs to the Computing section rather than to a school year, because computing is not something one grade owns. Anyone learning ai & ml can pin it up — a beginner, a student mid-course, or someone revising years later.
- When should you use the Tokens & Cost poster?
- Long context is charged on every single call. It is the largest hidden cost in most applications. A wall chart earns its place by being glanceable from where the work is happening, so Tokens & Cost belongs on the wall where that computing work actually happens, within glancing distance, rather than filed away.
- What other posters go with Tokens & Cost?
- Embeddings, Evaluating AI Output and LLM Vocabulary sit alongside Tokens & Cost in the Computing section. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.EmbeddingsEvaluating AI OutputLLM Vocabulary
- Is the Tokens & Cost poster free to download and print?
- Yes. Tokens & Cost downloads as a free PDF with no account, no email and no watermark, like everything else in the Computing section. Print as many copies as you like for a home, a classroom, a library or a tutoring group; reselling the file is the only thing the licence rules out.Read the licence
- What size does the Tokens & Cost poster print at?
- Tokens & Cost is a vector PDF laid out for US Letter, and prints on A4 with Fit to page — the same file, no separate download. Because every mark on it is drawn rather than photographed, it stays sharp enlarged to A3, A2 or A1 at a copy shop. Colour carries emphasis only, so a greyscale print of Tokens & Cost loses nothing.Printing guide
Related posters
Charts that sit alongside Tokens & Cost on the same wall.
Browse every Computing poster, or start from the full catalogue.