MIDI Note to Audio Frequency Calculator

This utility calculates the audio frequency and MIDI note name from any MIDI note number. It can display frequencies based on any user-defined reference pitch (for A above middle C) between 416 – 466 Hz (default is A = 440 Hz). It also displays the MIDI note name derived from any of the 3 common standards; Middle C = C3, C4 or C5 (default is C4). You can press Play to hear the note at the frequency displayed and you can change the pitch, waveform and volume whether or not sound is playing.

I’ve added a choice of waveforms for playback (because I can! ;)) but do bear in mind that since the default sine wave consists of only the fundamental it is the only pure waveform; all the others contain overtones of one sort or another:


On some Ubuntu/Debian Linux systems it’s possible that the waveform graphics may display incorrectly. Installing the ttf unifont package should fix this issue (from a terminal window, run: sudo apt install ttf-unifont).

On Mac systems, this should now work correctly in Safari (unfortunately, I still can’t test it though as I don’t own a Mac). Let me know if you encounter any problems.

MIDI Note to Audio Frequency Calculator by Colin Crawley
MIDI note to Audio Frequency
440 Hz
Play Sound


If you find this useful and/or have any comments or suggestions then do let me know via the comment section below.

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