What counts as a token

The unit Claude charges for

A token is roughly 4 characters of English text — about ¾ of a word. It's the unit Claude uses to measure and price everything it reads and writes.

Quick estimates

• 1 word ≈ 1.3 tokens
• 1 sentence ≈ 15–20 tokens
• 1 page of text ≈ 500–750 tokens
• 1,000 tokens ≈ 750 words

Everything counts

Everything in your request counts — system prompts, conversation history, uploaded files converted to text, tool definitions, and tool results. It all adds up before Claude writes a single word back.