Musical note generator

Play any note from C0 to B8 as a steady tone, at 440 Hz or the pitch your ensemble tunes to.

440 Hz

Octave4

A4 reference

WaveformSine

Volume-15 dB

Space plays or stops · ← → one semitone · ↑ ↓ one octave

How to play a note

Pick a note and an octave, then press Play or the Space bar. On a keyboard, ← and → step a semitone and ↑ and ↓ an octave, so you can walk a scale without looking. Change the A4 reference to tune to something other than 440 Hz: 442 Hz for many European orchestras, 415 Hz for Baroque music, or 432 Hz.

Note frequency chart

The frequency of every note from C0 to B8 at standard concert pitch. Middle C is C4, the A above it is A4 at 440 Hz, and each octave up doubles the frequency.

Equal temperament, A4 = 440 Hz. Rows are notes, columns are octaves.
Note	0	1	2	3	4	5	6	7	8
C	16.35	32.70	65.41	130.81	261.63	523.25	1047	2093	4186
C♯	17.32	34.65	69.30	138.59	277.18	554.37	1109	2217	4435
D	18.35	36.71	73.42	146.83	293.66	587.33	1175	2349	4699
D♯	19.45	38.89	77.78	155.56	311.13	622.25	1245	2489	4978
E	20.60	41.20	82.41	164.81	329.63	659.26	1319	2637	5274
F	21.83	43.65	87.31	174.61	349.23	698.46	1397	2794	5588
F♯	23.12	46.25	92.50	185.00	369.99	739.99	1480	2960	5920
G	24.50	49.00	98.00	196.00	392.00	783.99	1568	3136	6272
G♯	25.96	51.91	103.83	207.65	415.30	830.61	1661	3322	6645
A	27.50	55.00	110.00	220.00	440.00	880.00	1760	3520	7040
A♯	29.14	58.27	116.54	233.08	466.16	932.33	1865	3729	7459
B	30.87	61.74	123.47	246.94	493.88	987.77	1976	3951	7902

A4 = 440 Hz, 442, 432 or 415?

A4 = 440 Hz has been concert pitch since 1939, and almost all recorded music uses it. Many European orchestras tune slightly higher, to 442 Hz, for a brighter sound; Baroque ensembles play at 415 Hz, close to a semitone lower. 432 Hz is popular online, but no study shows it is healthier or more relaxing; it simply sounds about a third of a semitone lower.

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Need a frequency, not a note?

Any frequency to a hundredth of a hertz, with sweeps, four waveforms and a shareable link.

Open the frequency generator

Frequently asked questions

Middle C is C4, about 261.63 Hz at standard pitch (A4 = 440 Hz). It sits roughly in the middle of a piano keyboard.

A4 is the A above middle C. Orchestras, tuners and most instruments tune to it, and since 1939 the standard has been 440 Hz.

Play each open string's note and tune until the string matches it: E2 (82.41 Hz), A2 (110 Hz), D3 (146.83 Hz), G3 (196 Hz), B3 (246.94 Hz) and E4 (329.63 Hz). A sine is easiest to compare against; a sawtooth is easier to hear on small speakers.

Switch the A4 reference to 432 Hz and every note moves down by about 32 cents, a third of a semitone. No research shows 432 Hz is healthier or calmer; it is a matter of taste. Most recorded music is at 440 Hz.

It is scientific pitch notation: the letter is the note and the number the octave, starting at C. C4 is middle C, and B3 is the note just below it. Each number up doubles the frequency.