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THE FEUTEX TOOLKIT

Musical Note Frequency

Calculate equal-tempered note frequencies with a configurable A4 tuning reference.

Music workspace● Runs in your browser
01 Your input
02 Your result
View or copy raw result data
Formulaf = A4 × 2^((MIDI − 69)/12)

How to use this tool

  1. Load the example or enter your own values in the labeled fields.
  2. Run the tool and review the result and assumptions.
  3. Copy or download the result for your workflow.

Try this example

{"note": "A4", "a4": 440}

Accuracy and scope

Twelve-tone equal temperament. Accepts sharps and flats; note octave convention uses C4 = MIDI 60.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.