| Guide | What it covers |
|---|---|
| How to estimate LLM API costs | The cost formula plus the four corrections that make budget estimates real: tokenizer differences, invisible tokens, caching, deprecations. |
| Sonnet 5 price increase (Sept 1, 2026) | Claude Sonnet 5 introductory pricing ends Aug 31, 2026 — what +50% does to a real workload, and your options. |
LLM API Cost Guides
Working notes on estimating and budgeting LLM API spend, built on the same verified pricing data as the table.