Dew point calculator

Calculate the dew point from air temperature and humidity.

Processed on your device. No file upload.

How to use this tool

  1. Enter your values or try the example.
  2. Run the tool and check the result.
  3. Save the result where a download is available.

Supported features & limits

Magnus approximation over water using a=17.62, b=243.12 °C. Valid input range −45 to 60 °C, relative humidity above 0% up to 100%. Not a mold diagnosis.

Formula reference

What happens to my files?

Your browser reads the file locally. File contents are not sent to our server. Closing or resetting this page clears the working result. Downloaded copies remain on your device.

Maintained by Roman Zmazhenko. Updated 1 November 2026.