Note Frequency Calculator
Find the frequency of any note in any octave — A4 is 440 Hz — and see the notes around it, the octave and the nearest guitar string.
A4
440.00 Hz
One octave up (A5) is 880.00 Hz; one octave down (A3) is 220.00 Hz.
This note in every octave
| Note | Frequency | Where you hear it |
|---|---|---|
| A0 | 27.50 Hz | Sub-bass — felt more than heard |
| A1 | 55.00 Hz | Sub-bass — felt more than heard |
| A2 | 110.00 Hz | Bass guitar range |
| A3 | 220.00 Hz | Low guitar / cello range |
| A4 | 440.00 Hz | Middle range — A4 is 440 Hz tuning pitch |
| A5 | 880.00 Hz | High guitar / violin range |
| A6 | 1760.00 Hz | Very high — piccolo range |
| A7 | 3520.00 Hz | Beyond most instruments |
| A8 | 7040.00 Hz | Beyond most instruments |
How it works: Frequency follows equal temperament: A4 = 440 Hz, and each semitone multiplies the frequency by 2^(1/12) ≈ 1.0595. The formula is f = 440 × 2^((MIDI − 69)/12).
Try next: Interval Calculator