Calculator

What will this actually cost?

Most pricing pages multiply tokens in by a rate and tokens out by another. On anything agentic that is the small half of the bill. Set a workload below and this prices the prompt cache too — reads and writes.

Your workload

Input tokens per call

Output tokens per call

Calls per day

Prompt cache

Cache hit rate: 90%

Cache writes per day

A coding agent re-sends its whole context on every turn. The cache makes that cheap to read — and each write still costs, at up to twice the input rate.

Cost per day for the workload above. A model that does not publish a figure this workload needs shows what is missing instead of a number.
Model	Vendor	Per day	Per call	Where it goes

Why the cache write is the line that matters

A prompt cache lets a vendor skip re-processing a prefix you have sent before, and charges you much less for those tokens — often a tenth of the input rate. The part that is easy to miss is that putting something into the cache costs more than sending it normally: vendors that publish the figure charge around 1.25× the input rate for a five-minute entry and 2× for an hour.

So a workload that rewrites its cache often can cost more than one that never caches at all. That is not an edge case — it is what happens when an agent edits its own context between turns. Set the cache writes above to a high number and watch the total move.