Convert Fahrenheit to Celsius

Subtract 32 and multiply by 5/9.

JavaScript Version 1.0.0 · MIT · .md

function fahrenheitToCelsius(fahrenheit) { return (fahrenheit - 32) * 5 / 9; }

Try in the local lab Download function

Input & expected output

Input

Expected output

The edge case

Input

-40

Expected output

-40

Know the limits

The inverse of Convert Celsius to Fahrenheit; results are not rounded.

The function above is the implementation used by the lab. The lab validates JSON types and caps size before execution; include equivalent validation when accepting untrusted input in your application.

Source & maintenance

Curated implementation; explicit input contract, edge case and limits. Original MDX retained as inert source evidence.

Maintained by Oveyon. Original source commit: 14b481cf60df. This edition’s file: contents/convert-fahrenheit-to-celsius.mdx in akamind/1loc, commit 0a77f131b22d. Read the license.

Local fixture scope · Node.js 22.23.2 · reviewed October 28, 2026. No external service is required.

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