Question 1

What note is 440 Hz?

Accepted Answer

440 Hz is A4 (the A above middle C), MIDI note 69. It is the standard tuning reference for Western music, also known as concert pitch.

Question 2

What MIDI note is middle C?

Accepted Answer

Middle C is C4, which corresponds to MIDI note number 60. Its frequency at standard A4=440 Hz tuning is approximately 261.63 Hz.

Question 3

How do I convert Hz to a note name?

Accepted Answer

Use the formula: MIDI = 69 + 12 × log₂(Hz / 440). Round to the nearest integer to get the closest MIDI note, then map it to a note name (C, C#, D…) and octave. The cents deviation shows how far the frequency is from the exact pitch.

Question 4

What frequency is A4 at 432 Hz tuning?

Accepted Answer

At A4=432 Hz tuning, A4 is 432 Hz. All other notes shift proportionally: C4 becomes approximately 256.87 Hz, and B4 becomes approximately 485.76 Hz.

Question 5

What is the frequency of C4 (middle C)?

Accepted Answer

At standard A4=440 Hz tuning, middle C (C4) is 261.63 Hz. At A4=432 Hz it is approximately 256.87 Hz, and at A4=415 Hz (Baroque tuning) it is approximately 247.74 Hz.

MIDI	Note (#)	Frequency (Hz)
12	C0
13	C#0
14	D0
15	D#0
16	E0
17	F0
18	F#0
19	G0
20	G#0
21	A0
22	A#0
23	B0
24	C1
25	C#1
26	D1
27	D#1
28	E1
29	F1
30	F#1
31	G1
32	G#1
33	A1
34	A#1
35	B1
36	C2
37	C#2
38	D2
39	D#2
40	E2
41	F2
42	F#2
43	G2
44	G#2
45	A2
46	A#2
47	B2
48	C3
49	C#3
50	D3
51	D#3
52	E3
53	F3
54	F#3
55	G3
56	G#3
57	A3
58	A#3
59	B3
60	C4
61	C#4
62	D4
63	D#4
64	E4
65	F4
66	F#4
67	G4
68	G#4
69	A4
70	A#4
71	B4
72	C5
73	C#5
74	D5
75	D#5
76	E5
77	F5
78	F#5
79	G5
80	G#5
81	A5
82	A#5
83	B5
84	C6
85	C#6
86	D6
87	D#6
88	E6
89	F6
90	F#6
91	G6
92	G#6
93	A6
94	A#6
95	B6
96	C7
97	C#7
98	D7
99	D#7
100	E7
101	F7
102	F#7
103	G7
104	G#7
105	A7
106	A#7
107	B7
108	C8

MIDI	Note (#)	Frequency (Hz)
12	C0
13	C#0
14	D0
15	D#0
16	E0
17	F0
18	F#0
19	G0
20	G#0
21	A0
22	A#0
23	B0
24	C1
25	C#1
26	D1
27	D#1
28	E1
29	F1
30	F#1
31	G1
32	G#1
33	A1
34	A#1
35	B1
36	C2
37	C#2
38	D2
39	D#2
40	E2
41	F2
42	F#2
43	G2
44	G#2
45	A2
46	A#2
47	B2
48	C3
49	C#3
50	D3
51	D#3
52	E3
53	F3
54	F#3
55	G3
56	G#3
57	A3
58	A#3
59	B3
60	C4
61	C#4
62	D4
63	D#4
64	E4
65	F4
66	F#4
67	G4
68	G#4
69	A4
70	A#4
71	B4
72	C5
73	C#5
74	D5
75	D#5
76	E5
77	F5
78	F#5
79	G5
80	G#5
81	A5
82	A#5
83	B5
84	C6
85	C#6
86	D6
87	D#6
88	E6
89	F6
90	F#6
91	G6
92	G#6
93	A6
94	A#6
95	B6
96	C7
97	C#7
98	D7
99	D#7
100	E7
101	F7
102	F#7
103	G7
104	G#7
105	A7
106	A#7
107	B7
108	C8

MIDI	Note (#)	Frequency (Hz)
12	C0
13	C#0
14	D0
15	D#0
16	E0
17	F0
18	F#0
19	G0
20	G#0
21	A0
22	A#0
23	B0
24	C1
25	C#1
26	D1
27	D#1
28	E1
29	F1
30	F#1
31	G1
32	G#1
33	A1
34	A#1
35	B1
36	C2
37	C#2
38	D2
39	D#2
40	E2
41	F2
42	F#2
43	G2
44	G#2
45	A2
46	A#2
47	B2
48	C3
49	C#3
50	D3
51	D#3
52	E3
53	F3
54	F#3
55	G3
56	G#3
57	A3
58	A#3
59	B3
60	C4
61	C#4
62	D4
63	D#4
64	E4
65	F4
66	F#4
67	G4
68	G#4
69	A4
70	A#4
71	B4
72	C5
73	C#5
74	D5
75	D#5
76	E5
77	F5
78	F#5
79	G5
80	G#5
81	A5
82	A#5
83	B5
84	C6
85	C#6
86	D6
87	D#6
88	E6
89	F6
90	F#6
91	G6
92	G#6
93	A6
94	A#6
95	B6
96	C7
97	C#7
98	D7
99	D#7
100	E7
101	F7
102	F#7
103	G7
104	G#7
105	A7
106	A#7
107	B7
108	C8

PITCAL

MIDI	Note (#)	Frequency (Hz)
12	C0
13	C#0
14	D0
15	D#0
16	E0
17	F0
18	F#0
19	G0
20	G#0
21	A0
22	A#0
23	B0
24	C1
25	C#1
26	D1
27	D#1
28	E1
29	F1
30	F#1
31	G1
32	G#1
33	A1
34	A#1
35	B1
36	C2
37	C#2
38	D2
39	D#2
40	E2
41	F2
42	F#2
43	G2
44	G#2
45	A2
46	A#2
47	B2
48	C3
49	C#3
50	D3
51	D#3
52	E3
53	F3
54	F#3
55	G3
56	G#3
57	A3
58	A#3
59	B3
60	C4
61	C#4
62	D4
63	D#4
64	E4
65	F4
66	F#4
67	G4
68	G#4
69	A4
70	A#4
71	B4
72	C5
73	C#5
74	D5
75	D#5
76	E5
77	F5
78	F#5
79	G5
80	G#5
81	A5
82	A#5
83	B5
84	C6
85	C#6
86	D6
87	D#6
88	E6
89	F6
90	F#6
91	G6
92	G#6
93	A6
94	A#6
95	B6
96	C7
97	C#7
98	D7
99	D#7
100	E7
101	F7
102	F#7
103	G7
104	G#7
105	A7
106	A#7
107	B7
108	C8