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equal-loudness calculator

This calculator displays equal-loudness contours in accordance with ISO 226:2003. It allows you to normalize to any contour and see relative differences.


Tab delimited text, trace and target curve files for Smaart are also available for download but are limited to the 20 Hz to 12,5 kHz frequency range as specified by the ISO standard.

file type: Microsoft Excel Open XML spreadsheet (.xlsx)


minimum requirements:

  • Excel 2007 or higher
  • Excel 2008 or higher


download calculator (registered users only):



download Smaart files: