Looptally

Worked example · rates dated 2026-09-27

Eight steps, not eight calls.

This is the example loaded in the calculator. The token counts are made up so the shape is easy to see. The prices are Claude Sonnet 5 list rates: $2 per million input tokens, $2.50 to write a 5-minute cache, $0.20 to read it, $10 per million output tokens.

The inputs

What the transcript does

Step 1 sends 3,100 tokens. Step 8 sends 9,750. Across the run the prompts add up to 51,400 input tokens, which is 16.6 times the first step, not 8 times. Of those, 9,750 are cache writes and 41,650 are cache reads. Output is 2,800 tokens.

The bill for this shape

Turn the cache off and this same run costs about $0.0701 more. One step with the cache on costs more than one step with it off, because you pay the write and never read it back. The receipt says so when that happens.

Open this example in the calculator

Change the token counts. These ones are not a benchmark, and the total is not an invoice. Retries, hidden reasoning, and a prefix too short to cache will not match.