Input, output and cached tokens

Your AI bill is built from three separately-priced token types:

Input tokens

Everything you send: system prompt, conversation history, retrieved context and the user’s message. Usually the largest and cheapest per-token portion.

Output tokens

What the model generates. Priced higher than input, often 3–5×, so long responses cost more than long prompts.

Cached input tokens

Input the provider has seen recently and can reuse. Billed at a steep discount (often 10–25% of the normal input price). Worth it when a large, stable prefix (a long system prompt or fixed context) repeats across many requests.

Set a cached-input percentage in the calculator to see the savings on your own workload. Not every model supports caching, and the calculator flags those.