Frequency to Note Calculator
Convert hertz to the nearest musical note, exact target frequency, and cents sharp or flat.
Closest note
A4
Exact target
440.00 Hz
Tuning offset
+0.0 cents
Very close to the target
How frequency becomes a note
Frequency measures how many times a sound wave repeats each second. A musical note describes where that frequency sits in a tuning system. In 12-tone equal temperament, every semitone multiplies frequency by 2 raised to one twelfth, and every octave doubles it.
Real performances rarely land on an exact table value. The cents result shows the smaller difference between your entered frequency and the nearest target. Zero cents is exact; positive values are sharp and negative values are flat.
| Frequency | Note | Reference |
|---|---|---|
| 110 Hz | A2 | Low A on guitar or a common bass-range reference |
| 220 Hz | A3 | One octave below concert A |
| 261.63 Hz | C4 | Middle C in scientific pitch notation |
| 440 Hz | A4 | Standard modern concert pitch |
| 880 Hz | A5 | One octave above concert A |
Need the complete table?
Browse every equal-tempered note from C0 through B8 at A4 = 440 Hz.
Open the note frequency chartMeasure a sound live
Use your microphone to estimate a live frequency and compare it with the calculation.
Open the pitch detector