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LLM API Cost Calculator

Input and output tokens are priced very differently (output is 5× input on most models), and a cached system prompt is billed at a fraction of the input rate. This calculator models all three. Prices are list rates as of September 2026 — edit any cell if yours differ.

Model$/M in$/M outCache readPer callPer month

Where the money goes

Sources: Anthropic pricing (official), OpenAI and Google list prices as published on their platform pages, checked 2026-09-14. Cache read rates: Anthropic 10% of input; OpenAI and Google 10–25% depending on model — approximated at the vendor's published rate. Long-context surcharges above 200K tokens are not modelled.

Spending more than you'd like? The Claude Token Economy Playbook covers caching, routing and context hygiene that cut bills 40–70%.

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A free tool by Sigma Foundry · no account needed · privacy