Piano Note Finder
Find any note on the piano keyboard — its name, octave, frequency and where it sits among the white and black keys.
A4
440.00 Hz
MIDI note: 69 · White or black key: White key · Octave: 4 (middle C is C4, 261.63 Hz)
Neighbouring notes
| Note | Frequency |
|---|---|
| G4 | 392.00 Hz |
| Ab4 | 415.30 Hz |
| A4 ← this note | 440.00 Hz |
| Bb4 | 466.16 Hz |
| B4 | 493.88 Hz |
How it works: Frequencies double every octave: A4 is 440 Hz, A5 is 880 Hz, A3 is 220 Hz. Each semitone multiplies the frequency by the 12th root of 2 (about 1.0595).
Try next: Fretboard Note Finder