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Note Frequency Calculator

Convert between musical notes and Hz.

Note → Frequency

A4
440.00 Hz

Frequency → Note

A4
0.0 cents
Reference table (C2 to B6)
C2
65.41
C#2
69.30
D2
73.42
D#2
77.78
E2
82.41
F2
87.31
F#2
92.50
G2
98.00
G#2
103.83
A2
110.00
A#2
116.54
B2
123.47
C3
130.81
C#3
138.59
D3
146.83
D#3
155.56
E3
164.81
F3
174.61
F#3
185.00
G3
196.00
G#3
207.65
A3
220.00
A#3
233.08
B3
246.94
C4
261.63
C#4
277.18
D4
293.66
D#4
311.13
E4
329.63
F4
349.23
F#4
369.99
G4
392.00
G#4
415.30
A4
440.00
A#4
466.16
B4
493.88
C5
523.25
C#5
554.37
D5
587.33
D#5
622.25
E5
659.26
F5
698.46
F#5
739.99
G5
783.99
G#5
830.61
A5
880.00
A#5
932.33
B5
987.77
C6
1046.50
C#6
1108.73
D6
1174.66
D#6
1244.51
E6
1318.51
F6
1396.91
F#6
1479.98
G6
1567.98
G#6
1661.22
A6
1760.00
A#6
1864.66
B6
1975.53

Equal temperament: each semitone is the 12th root of 2 above the previous note. A4 is 440 Hz by international standard, but some orchestras tune to 442 or 443. Cents are 1/100th of a semitone.

About

Pick a note and octave, get the frequency in hertz. Or paste a frequency, get the closest note plus how many cents off it is. Useful when you're tuning instruments, troubleshooting feedback, or sanity-checking a synth.

How to use

  1. Pick a note and octave to see the frequency.
  2. Paste a frequency to find the closest note.

FAQ

Why does A4 default to 440 Hz?+

ISO 16:1975 sets concert pitch at A4 = 440 Hz. Many orchestras tune to 442 or 443. Baroque ensembles often use 415. Change the reference and the whole table shifts.