Note β Frequency Converter (Hz)
Convert musical note names to frequency in Hz and back, with adjustable A4 tuning.
π Runs entirely in your browser. Your input and output are never sent to a server or stored β fully private.
Equal temperament Β· f = A4 Γ 2^((n β 69) / 12)
About this tool
Note β Frequency converts any musical note name to its pitch in hertz and back again, with the A4 reference adjustable from the standard 440 Hz to whatever tuning you need. It is handy for setting synth oscillators, calibrating a tuner, sound design or simply checking the exact frequency of a note. The conversion happens instantly in your browser.
Frequently asked questions
What frequency is A4?
A4 is 440 Hz by default β the modern concert-pitch standard β but you can set it to 432, 442 or any reference, and every other note is recalculated from it. Going up one octave doubles the frequency, and down one octave halves it.
How is a note's frequency calculated?
Equal temperament splits the octave into twelve equal semitones, so each step multiplies the frequency by the twelfth root of two (about 1.0595). The tool applies that from your chosen A4 to give the exact hertz value for any note.