> For the complete documentation index, see [llms.txt](https://srwa.gitbook.io/srwa-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://srwa.gitbook.io/srwa-docs/core-calculations/apr.md). # APR Annual percentage rate (APR) refers to the yearly interest generated by a sum that's charged to borrowers or paid to lenders. APR is based on borrow rate, which is calculated based on kink: If the utilization is less than kink then the borrow rate is: borrow\_rate = base + base\_multiplier \* utilization Otherwise, it's: borrow\_rate = base + base\_multiplier \* kink + multiplier \* (utilization - kink) Base, Base Multiplier, Multiplier and kink are the pool parameters that are set by the Admins and they can be changed if needed. When we have the borrow rate it's used to calculate APR, with the passage of time: borrow\_apr = borrow\_rate \* (current\_epoch - last\_interaction\_epoch) / (365 \* 24 \* 60 / 5) --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://srwa.gitbook.io/srwa-docs/core-calculations/apr.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.