432 Hz test · 432 vs 440 tuner
432 vs 440 Tuner
432 Hz tuning sets the note A to 432 Hz instead of the standard 440 Hz, so every note sits 31.77 cents lower, about a third of a semitone. Sing or play into the tuner to see how far you are from both tunings at once, or pick a note, see both frequencies and hear 440 and 432 back to back.
No mic? Pick a note
Listen
- Note
- At A = 440
- At A = 432
- Gap
- Root at 440
- Root at 432
- Whole number
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The link reopens this note, and the reading if there is one.
How it works
Same notes, a third of a semitone apart
1. One formula, two starting points
Modern tuning splits each octave into 12 equal steps. Each step multiplies the frequency by the twelfth root of 2, about 1.0595, and twelve steps double it. Every note is worked out from A: frequency = A × 2(n − 69) ÷ 12, where n is the note's number, 69 for the A above middle C. Swap A = 440 for A = 432 and every note is multiplied by 432 ÷ 440. That is always 31.77 cents lower, and 100 cents make a semitone.
2. How the tuner hears a note
The tuner takes 2,048 samples of sound at a time, about a twentieth of a second, and compares the sound with a delayed copy of itself. The delay where the copy lines up best is one full wave, the period, and the frequency is 1 divided by the period. This is the YIN method, with a small curve fit between samples for a finer answer. Quiet sound is ignored, and each reading is the middle value of the last 5, so the number does not jump. It reads from 60 Hz to 1500 Hz.
3. Two meters, one dial
The A = 440 meter shows cents from the nearest note in standard tuning, and the A = 432 meter from the nearest note in 432 tuning. A note tuned to 432 reads −31.8 on the first and 0 on the second. On the dial one full turn is one semitone: 440 sits at the top and 432 sits 31.77 cents back, a little under a third of the way around.
4. Where the 9 comes from
432 has digital root 9, since 4 + 3 + 2 = 9. Double or halve it and it stays a multiple of 9, so all its whole number A's, 27, 54, 108, 216, 432, 864 and 1728, root to 9. 440 roots to 8, and its A's 55, 110, 220, 440, 880 and 1760 walk 1 2 4 8 7 5, the same doubling loop as the vortex. The other notes are not whole numbers in either tuning. C4 is 261.63 at 440 and 256.87 at 432, so the tuner shows the root of the rounded number and says so.
Real vs legend
What is history and what is story
| Claim | Status |
|---|---|
| A = 440 was agreed at an international conference in London in 1939 and became the ISO 16 standard in 1955, reaffirmed in 1975. | Real |
| A = 432 is 31.77 cents below A = 440 on every note, about a third of a semitone. | Real |
| The whole number A's at 432 (27, 54, 108, 216, 432, 864, 1728) all have digital root 9. The A's at 440 (55, 110, 220, 440, 880, 1760) walk 1 2 4 8 7 5. | Real |
| Orchestras vary, and many tune to 441 to 443. | Real |
| In 1884 an Italian government decision set A = 432 for military bands, a pitch Verdi supported. It is sometimes called Verdi pitch. | Real |
| Most listeners cannot name which tuning they hear without a reference. | Real |
| 432 Hz is the frequency of the universe, or of nature. | Legend |
| 432 Hz heals DNA or the body. | Legend |
| Cymatics proves 432 is better. | Legend |
| 440 was pushed by the Nazis or Goebbels to agitate people. | No source |
Questions
432 vs 440 FAQ
What is the difference between 432 Hz and 440 Hz?
They are two choices for the pitch of the note A above middle C. Every other note is built from A, so moving A from 440 to 432 moves every note down by the same amount: 31.77 cents, about a third of a semitone. On A the gap is 8 Hz. On middle C it is 261.63 Hz against 256.87 Hz, a gap of 4.76 Hz.
How can I test if a song is in 432 Hz?
Press Start listening and play the song near your device. Watch a few long, steady notes. If the needle sits near 0 on the A = 432 meter and near −32 on the A = 440 meter, the song is tuned close to 432. Check more than one note, because singers bend pitch and many orchestras tune a little above 440, often 441 to 443.
Can people hear the difference between 432 and 440?
Played one after the other, many people can hear that one is a little lower. Heard alone, without a reference, most listeners cannot name which tuning they are hearing. Press A / B to hear the same note in both tunings, taking turns.
Why is 440 Hz the standard?
An international conference in London agreed on A = 440 in 1939, and it became the ISO 16 standard in 1955, reaffirmed in 1975. Before that the pitch of A varied from city to city. Even now orchestras vary, and many tune to 441 to 443.
Why do 432 Hz notes add up to 9?
Only the A's do. 4 + 3 + 2 = 9, and every octave of A doubles or halves the number: 27, 54, 108, 216, 432, 864 and 1728 all have digital root 9, because doubling a multiple of 9 gives another multiple of 9. The A's at 440 are 55, 110, 220, 440, 880 and 1760, with roots 1 2 4 8 7 5, the doubling loop. In equal temperament the other notes are not whole numbers in either tuning.
Is 432 Hz healing, or the frequency of the universe?
There is no good evidence for either claim. Nothing reliable shows that 432 heals the body or DNA, and 432 is not special in nature: the hertz is counted per second, a human unit of time. The story that the Nazis or Goebbels pushed 440 to agitate people has no source. Cymatics patterns change with every frequency, so they do not show that one tuning is better. If 432 sounds nicer to you, that is a fine reason to use it.
Does the tuner need a microphone?
No. Pick a note and an octave to see both frequencies, the gap and the digital roots, and to play both versions. If you do use the mic, the sound is measured on your device and is not recorded or sent anywhere.
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