Look up the exact frequency of any note, or find the nearest note for a frequency — with adjustable A4 reference for 432 Hz and other tunings.
Note ↔ Frequency Converter
Equal temperament: f = A4 × 2^((n − 69) / 12), where n is the MIDI note number (A4 = MIDI 69). Change A4 to 432 Hz to explore alternate tunings.
How it works
In equal temperament each octave doubles in frequency and is split into twelve equal semitones, so a note’s frequency is A4 × 2^((n − 69) ÷ 12), where n is its MIDI number and A4 is your reference pitch. Enter a frequency in the second box to get the nearest note and how many cents sharp or flat it is.
FAQ
What is A4 = 440 Hz?
440 Hz is the modern concert-pitch standard for the A above middle C. Some musicians prefer 432 Hz — change the A4 box to explore alternate tunings.
What are cents?
A cent is one hundredth of a semitone. The converter shows how far a frequency is from the nearest in-tune note, which is handy for tuning and analysis.