# ABV Calculator The ABV Calculator estimates the resulting alcohol by volume from original and final gravity values. The calculator uses the simple conversion formula: ``` ABV = (OG - FG) x 131.25 ``` Note that due to the manner in which the RAPT Portal calculator handles rounding of decimals, the calculated gravity may differ from this calculator --- # Agent Instructions: 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: ``` GET https://docs.rapt.io/tools/abv-calculator.md?ask= ``` The question should be specific, self-contained, and written in natural language. 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.