Octave 4 Piano Notes — Frequencies & Keys
12 keys from C4 (261.63 Hz) to B4 (493.88 Hz).
| Note | Frequency | MIDI | Key |
|---|---|---|---|
| C4 | 261.63 Hz | 60 | 40 of 88 |
| C#4 | 277.18 Hz | 61 | 41 of 88 |
| D4 | 293.66 Hz | 62 | 42 of 88 |
| D#4 | 311.13 Hz | 63 | 43 of 88 |
| E4 | 329.63 Hz | 64 | 44 of 88 |
| F4 | 349.23 Hz | 65 | 45 of 88 |
| F#4 | 369.99 Hz | 66 | 46 of 88 |
| G4 | 392.00 Hz | 67 | 47 of 88 |
| G#4 | 415.30 Hz | 68 | 48 of 88 |
| A4 | 440.00 Hz | 69 | 49 of 88 |
| A#4 | 466.16 Hz | 70 | 50 of 88 |
| B4 | 493.88 Hz | 71 | 51 of 88 |