Prompt Caching Savings Calculator
See when a long repeated system prompt is worth caching.
Free · no signup · runs in your browserWhat this calculator is for
Prompt caching matters most when a large, stable prefix is reused across many requests. The calculator separates cacheable and changing input, then applies an estimated hit rate.
The math
Actual invoices can differ because providers may apply long-context pricing, caching rules, batch rates, tool-call fees, regional processing, negotiated contracts, taxes, or future pricing changes. Treat the output as a planning estimate.
Pricing sources
Current model rates are sourced from official provider pricing pages and verified on August 28, 2026. The methodology page records the source links and known limitations.
Frequently asked question
What content is a good caching candidate?
Large repeated system prompts, tool definitions, policies, schemas and stable document context are common candidates when a provider supports prompt caching.
Can I use this estimate for a production budget?
Use it to create scenarios and catch order-of-magnitude mistakes. Before committing spend, verify the selected model's live provider pricing and compare the estimate with actual usage telemetry.