What MIDI number is A4?

A4 is MIDI note 69, at 440 Hz. It is the anchor for the whole system: the formula f = 440 × 2^((m − 69) / 12) is built around it.

What MIDI number is middle C?

Middle C is MIDI note 60 (C4), at 261.63 Hz. Some manufacturers label this C3, but the MIDI number is always 60.

What is the range of MIDI note numbers?

MIDI note numbers run from 0 to 127 — C−1 (8.18 Hz) to G9 (12543.85 Hz). A standard 88-key piano covers only 21 (A0) to 108 (C8).

How do you convert a MIDI number to hertz?

Use f = 440 × 2^((m − 69) / 12). For example MIDI 60 gives 440 × 2^((60 − 69) / 12) = 261.63 Hz.

How do you convert hertz to a MIDI number?

Use m = 69 + 12 × log2(f / 440), then round to the nearest whole number. 440 Hz gives exactly 69; 261.63 Hz gives 60.

Do all MIDI instruments use the same frequencies?

The nominal mapping is the same, but tuning is not. Orchestras may tune to 442 or 443 Hz, some historical ensembles use 415 Hz, and the numbers here assume the equal-tempered 440 Hz default.

MIDI Note Frequency Chart — All 128 MIDI Notes in Hz

Every MIDI note number from 0 to 127, with its note name, octave, key colour and exact frequency in hertz. Values use twelve-tone equal temperament with A4 = 440 Hz, which is what virtually all modern MIDI instruments and DAWs assume.

Convert a MIDI number interactively

Want a single value, or need to go the other way — from hertz back to a note? Use the MIDI to frequency converter. It converts in all three directions and shows the note on a piano keyboard.

Complete MIDI note number table (0–127)

A4 (MIDI 69, 440 Hz) and middle C (MIDI 60) are highlighted. Click any note name to see that pitch class across every octave.

MIDI	Note	Octave	Key	Frequency (Hz)	Period (ms)
0	C-1	-1	White	8.18	122.3122
1	C♯-1	-1	Black	8.66	115.4473
2	D-1	-1	White	9.18	108.9678
3	D♯-1	-1	Black	9.72	102.8519
4	E-1	-1	White	10.30	97.0793
5	F-1	-1	White	10.91	91.6306
6	F♯-1	-1	Black	11.56	86.4878
7	G-1	-1	White	12.25	81.6336
8	G♯-1	-1	Black	12.98	77.0519
9	A-1	-1	White	13.75	72.7273
10	A♯-1	-1	Black	14.57	68.6454
11	B-1	-1	White	15.43	64.7926
12	C0	0	White	16.35	61.1561
13	C♯0	0	Black	17.32	57.7237
14	D0	0	White	18.35	54.4839
15	D♯0	0	Black	19.45	51.4259
16	E0	0	White	20.60	48.5396
17	F0	0	White	21.83	45.8153
18	F♯0	0	Black	23.12	43.2439
19	G0	0	White	24.50	40.8168
20	G♯0	0	Black	25.96	38.5259
21	A0	0	White	27.50	36.3636
22	A♯0	0	Black	29.14	34.3227
23	B0	0	White	30.87	32.3963
24	C1	1	White	32.70	30.5781
25	C♯1	1	Black	34.65	28.8618
26	D1	1	White	36.71	27.2419
27	D♯1	1	Black	38.89	25.7130
28	E1	1	White	41.20	24.2698
29	F1	1	White	43.65	22.9077
30	F♯1	1	Black	46.25	21.6219
31	G1	1	White	49.00	20.4084
32	G♯1	1	Black	51.91	19.2630
33	A1	1	White	55.00	18.1818
34	A♯1	1	Black	58.27	17.1614
35	B1	1	White	61.74	16.1982
36	C2	2	White	65.41	15.2890
37	C♯2	2	Black	69.30	14.4309
38	D2	2	White	73.42	13.6210
39	D♯2	2	Black	77.78	12.8565
40	E2	2	White	82.41	12.1349
41	F2	2	White	87.31	11.4538
42	F♯2	2	Black	92.50	10.8110
43	G2	2	White	98.00	10.2042
44	G♯2	2	Black	103.83	9.6315
45	A2	2	White	110.00	9.0909
46	A♯2	2	Black	116.54	8.5807
47	B2	2	White	123.47	8.0991
48	C3	3	White	130.81	7.6445
49	C♯3	3	Black	138.59	7.2155
50	D3	3	White	146.83	6.8105
51	D♯3	3	Black	155.56	6.4282
52	E3	3	White	164.81	6.0675
53	F3	3	White	174.61	5.7269
54	F♯3	3	Black	185.00	5.4055
55	G3	3	White	196.00	5.1021
56	G♯3	3	Black	207.65	4.8157
57	A3	3	White	220.00	4.5455
58	A♯3	3	Black	233.08	4.2903
59	B3	3	White	246.94	4.0495
60	C4	4	White	261.63	3.8223
61	C♯4	4	Black	277.18	3.6077
62	D4	4	White	293.66	3.4052
63	D♯4	4	Black	311.13	3.2141
64	E4	4	White	329.63	3.0337
65	F4	4	White	349.23	2.8635
66	F♯4	4	Black	369.99	2.7027
67	G4	4	White	392.00	2.5511
68	G♯4	4	Black	415.30	2.4079
69	A4	4	White	440.00	2.2727
70	A♯4	4	Black	466.16	2.1452
71	B4	4	White	493.88	2.0248
72	C5	5	White	523.25	1.9111
73	C♯5	5	Black	554.37	1.8039
74	D5	5	White	587.33	1.7026
75	D♯5	5	Black	622.25	1.6071
76	E5	5	White	659.26	1.5169
77	F5	5	White	698.46	1.4317
78	F♯5	5	Black	739.99	1.3514
79	G5	5	White	783.99	1.2755
80	G♯5	5	Black	830.61	1.2039
81	A5	5	White	880.00	1.1364
82	A♯5	5	Black	932.33	1.0726
83	B5	5	White	987.77	1.0124
84	C6	6	White	1046.50	0.9556
85	C♯6	6	Black	1108.73	0.9019
86	D6	6	White	1174.66	0.8513
87	D♯6	6	Black	1244.51	0.8035
88	E6	6	White	1318.51	0.7584
89	F6	6	White	1396.91	0.7159
90	F♯6	6	Black	1479.98	0.6757
91	G6	6	White	1567.98	0.6378
92	G♯6	6	Black	1661.22	0.6020
93	A6	6	White	1760.00	0.5682
94	A♯6	6	Black	1864.66	0.5363
95	B6	6	White	1975.53	0.5062
96	C7	7	White	2093.00	0.4778
97	C♯7	7	Black	2217.46	0.4510
98	D7	7	White	2349.32	0.4257
99	D♯7	7	Black	2489.02	0.4018
100	E7	7	White	2637.02	0.3792
101	F7	7	White	2793.83	0.3579
102	F♯7	7	Black	2959.96	0.3378
103	G7	7	White	3135.96	0.3189
104	G♯7	7	Black	3322.44	0.3010
105	A7	7	White	3520.00	0.2841
106	A♯7	7	Black	3729.31	0.2681
107	B7	7	White	3951.07	0.2531
108	C8	8	White	4186.01	0.2389
109	C♯8	8	Black	4434.92	0.2255
110	D8	8	White	4698.64	0.2128
111	D♯8	8	Black	4978.03	0.2009
112	E8	8	White	5274.04	0.1896
113	F8	8	White	5587.65	0.1790
114	F♯8	8	Black	5919.91	0.1689
115	G8	8	White	6271.93	0.1594
116	G♯8	8	Black	6644.88	0.1505
117	A8	8	White	7040.00	0.1420
118	A♯8	8	Black	7458.62	0.1341
119	B8	8	White	7902.13	0.1265
120	C9	9	White	8372.02	0.1194
121	C♯9	9	Black	8869.84	0.1127
122	D9	9	White	9397.27	0.1064
123	D♯9	9	Black	9956.06	0.1004
124	E9	9	White	10548.08	0.0948
125	F9	9	White	11175.30	0.0895
126	F♯9	9	Black	11839.82	0.0845
127	G9	9	White	12543.85	0.0797

How MIDI numbers work

MIDI note numbers are simply a linear count of semitones. Each step of 1 is one semitone, so each step of 12 is one octave. Three anchors are worth memorising:

MIDI 60 = C4 — middle C, 261.63 Hz.
MIDI 69 = A4 — the tuning reference, 440.00 Hz.
MIDI 21 = A0 — the lowest note on an 88-key piano, 27.50 Hz.

The full range runs from MIDI 0 (C−1, 8.18 Hz) to MIDI 127 (G9, 12543.85 Hz). An ordinary 88-key piano only uses 21 to 108 of these, which is why the piano note frequency chart is a subset of this table.

The formula

To turn a MIDI number m into a frequency:

f = 440 × 2^{(m − 69) / 12}

and to go back the other way:

m = 69 + 12 × log₂(f / 440)

Rounding m to the nearest whole number gives you the closest MIDI note for any frequency, which is what the converter does when you type in hertz.

A note on octave numbering

MIDI numbers are unambiguous, but the names beside them are not universal. This table uses scientific pitch notation, in which middle C is C4 and A4 is 440 Hz. Yamaha and some DAWs call middle C “C3” instead — same key, same frequency, different label. When in doubt, quote the MIDI number. See middle C frequency for the full explanation.

Frequently asked questions

What MIDI number is A4?: A4 is MIDI note 69, at 440 Hz. It is the anchor for the whole system: the formula f = 440 × 2^((m − 69) / 12) is built around it.
What MIDI number is middle C?: Middle C is MIDI note 60 (C4), at 261.63 Hz. Some manufacturers label this C3, but the MIDI number is always 60.
What is the range of MIDI note numbers?: MIDI note numbers run from 0 to 127 — C−1 (8.18 Hz) to G9 (12543.85 Hz). A standard 88-key piano covers only 21 (A0) to 108 (C8).
How do you convert a MIDI number to hertz?: Use f = 440 × 2^((m − 69) / 12). For example MIDI 60 gives 440 × 2^((60 − 69) / 12) = 261.63 Hz.
How do you convert hertz to a MIDI number?: Use m = 69 + 12 × log2(f / 440), then round to the nearest whole number. 440 Hz gives exactly 69; 261.63 Hz gives 60.
Do all MIDI instruments use the same frequencies?: The nominal mapping is the same, but tuning is not. Orchestras may tune to 442 or 443 Hz, some historical ensembles use 415 Hz, and the numbers here assume the equal-tempered 440 Hz default.

Last updated: 2026-09-01