432 Hz vs 440 Hz: What the Two Numbers Actually Mean
If you have shopped for a singing bowl or a gong, you have probably seen "432 Hz" on a listing and wondered whether you need it. The short answer: 432 Hz and 440 Hz are tuning references, two different settings for where A in the 4th octave (A4) sits. A bowl or gong labeled "432 Hz" usually does not literally ring at 432 Hz; the label normally refers to the tuning reference used.
If you only remember three things
- 432 and 440 are tuning references: settings for where A in the 4th octave (A4) sits. A bowl or gong labeled "432 Hz" usually does not literally ring at 432 Hz.
- Switching your tuner from one reference to the other does not change the sound of an instrument you already own. It changes how that sound is described.
- The difference matters most when you play several instruments together.
What does 432 Hz actually mean?
Every sound is a vibration. Strike a gong and its face flexes back and forth; strike a bowl and its walls do the same, very fast, pushing on the air around them. Hertz (Hz) counts how many times per second that happens. More vibrations per second sounds higher; fewer sounds lower.
Notes (C, D, E, A and so on) are names for particular pitches, and each name repeats up the scale, once per octave. Musicians add a number to say which octave they mean: A4 is the A in the 4th octave, the A just above middle C on a piano.
The names have to be pinned to something. Someone has to decide exactly how fast A4 vibrates, and once that is decided, every other note falls into place around it, like the marks on a ruler. That pinning point is the tuning reference.
A4 = 440 Hz is the international standard, and the common default for tuners and many instruments; some orchestras tune slightly higher, to 442 or 443. A4 = 432 Hz is an alternative reference that pins the same note a little lower. Move the pin and every note on the ruler moves with it, all by the same small amount: about a third of the step between two neighboring piano keys. The difference is easiest to hear in a direct side-by-side comparison.
Two situations get mixed up here, and separating them clears up most of the confusion:
Measuring an instrument you already have. Open a tuner app and change its calibration from 440 to 432. The bowl or gong in front of you has not changed. Only the ruler you are measuring it against has, so the tuner describes the same sound with a different reading.
Making an instrument to a reference. A middle C made to match A4 = 440 Hz and a middle C made to match A4 = 432 Hz are genuinely different pitches: about 262 vibrations per second against about 257. Two instruments built to different references really do sound slightly apart.
"Is this bowl or gong 432 Hz?"
This is the question we are asked most, and it comes from a natural mix-up: reading "432 Hz" as the sound the instrument makes. It isn't.
How fast an instrument vibrates is set by the instrument itself. For a bowl, that means its size, its wall thickness and what it is made of; for a gong, its size, thickness, metal and hammering. (Our guides to choosing the right frequency for your singing bowl and to gong frequency cover that side.)
Suppose a bowl physically rings at about 262 Hz. On a tuner set to A4 = 440 Hz, that is essentially middle C. Change the tuner to A4 = 432 Hz and the bowl still rings at 262 Hz, but now the tuner reads C, about 32 cents sharp. (A cent is a hundredth of the step between neighboring piano keys; more on that below.)
Now a gong whose note sits at about 73 Hz. On the 440 reference, that is a low D. On the 432 reference, it is the same D, a little sharp. Either way, the gong is vibrating at around 73 Hz, nowhere near 432.
So "432 Hz" on a listing usually means the instrument's note was named or tuned against the 432 reference. It rarely means the instrument literally rings at 432 Hz; on that reference, only an A4 would.
432 Hz vs 440 Hz: what changes when you play
Playing one instrument by itself: the reference does not change that instrument's sound. It mainly changes how we describe its pitch. If you are choosing between two instruments, one made to each reference, you are choosing between two slightly different pitches, and your ears are the right judge.
Playing instruments together: this is where it counts, for bowls and gongs alike. Two instruments aiming at the "same" note from different references end up slightly apart, and you hear it as beating or roughness between them. If you are building a group of instruments, keep them on one reference, or check each one's note before you pair them. Our harmonized bowl sets and Grotta Sonora gong sets are matched by complementary musical intervals, so the reference behind each note matters for both.
How much it matters for a particular gong depends on the gong. Some gongs hold a very steady main note, and players pair and harmonize them by that note exactly as they would bowls; for those, 432 vs 440 matters just as much. Others spread their energy across a wide, shifting range of tones, and the note name tells you less. The recording tells you which kind you are hearing.
Buying a bowl or gong labeled "432 Hz": because sellers use the phrase in different ways, look for three concrete pieces of information: the instrument's note, its measured frequency or cents reading, and the tuning reference used. Every bowl we sell carries its note and cents on the 440 reference, with its 432 equivalent on the product page, and most of our gong listings name each gong's note.
The technical detail: why the difference is 31.77 cents
You don't need this section to choose a bowl or gong, but here is the math if you want it.
Musicians measure small pitch differences in cents: the step between two neighboring piano keys (a semitone) is divided into 100 of them. The gap between the two references is 31.77 cents, a little under a third of a semitone, and it is the same for every note in every octave.
In hertz, the gap depends on where you look. At A4, the note the two references are based on, the gap is 8 Hz: 440 against 432. An octave lower it is 4 Hz; an octave higher, 16 Hz. That is why cents are the honest unit: they stay put while hertz do not.
How to read a note on either reference
Every Crystal Tones bowl we sell is labeled with three things: note, octave and cents. A reading of A#4+20, for example, means the note A#, in the octave that starts at middle C, 20 cents sharp of exact, or about 472 Hz. Most of our gong listings name a note for each gong, too.
All Raven Sounds note readings are based on A4 = 440 Hz, and every Crystal Tones bowl's product page also states its approximate reading on the 432 reference, so you never have to do the arithmetic for one of our bowls. For a gong, or any other instrument, it is simple: because the 432 marks sit lower, the same instrument reads about 32 cents higher against them. Add 32 to the cents figure, round to the nearest 5, and if the result passes 50, it is now closer to the next note up, so it rolls over to that note name.
| Reading on the 440 reference | Same instrument on the 432 reference |
|---|---|
| A#4 +20 | A#4 +50 |
| D4 +0 | D4 +30 |
| F4 +25 | F#4 −45 |
Nothing about the instrument changed in that table. Only the ruler moved. A label that says only "C" cannot be converted this way, and one that says only "432 Hz" is telling you less, not more.
Why 440, and where 432 came from
For centuries, the pitch of A4 varied widely from city to city and orchestra to orchestra. France fixed it at 435 Hz by law in 1859, and much of Europe followed. An international conference in London recommended A4 = 440 Hz in 1939; the International Organization for Standardization adopted it in 1955 and confirmed it in 1975 as ISO 16, which remains the current standard.
A4 = 432 Hz is an alternative tuning reference, sometimes called "Verdi tuning" after the composer Giuseppe Verdi, who argued for a lower standard pitch. It is not the current international standard.
Bowls, gongs, and how steady a note is
Neither a bowl nor a gong makes a single pure tone. Both sound a main note, called the fundamental, along with many overtones above it, and neither set of overtones lines up in the neat whole-number steps of a textbook harmonic series.
The difference is one of tendency. Bowls tend to give a clearer, steadier fundamental, though it can still vary a little and the overtones are rich. Gongs tend to spread across a wider range of tones, and their fundamental is often less stable than a bowl's. But every gong is different: some have a rock-steady fundamental, others move around a great deal. That is why we list a note for most of our gongs, and why the recording matters as much as the note. The gong frequency guide linked above covers the physics.
What we don't claim
There is a large body of writing that attributes physical, physiological, or cosmic properties to 432 Hz specifically. We don't publish any of it. We sell instruments, and we state only what we can stand behind. The history is real and the arithmetic is real; claims about what a number does to a person are not something we assert.
What we will say is this: preference is a perfectly good reason. If you play on the 432 reference because you like how it sits, that needs no theory behind it.
Questions
Is this bowl or gong 432 Hz? Almost certainly not in the way the question means. An instrument rings at whatever speed its size and construction give it; 432 and 440 are two references for naming that note. Our notes are given on the 440 reference, and every bowl's product page also gives the 432 equivalent.
Is 432 Hz better than 440 Hz? Neither is objectively better. They are two reference points about a third of a semitone apart. Choose the instrument whose sound you like, and keep instruments you play together on one reference.
Can I retune a crystal singing bowl to 432? Not in any practical sense. A bowl's pitch is set by its physical form (diameter, wall thickness, material) when it is made. You can describe its fixed pitch relative to either reference, but that does not physically retune the bowl.
Is 440 Hz an official standard? Yes. ISO 16 specifies A4 = 440 Hz and is the current international standard.
Do you sell 432 Hz bowls or gongs? Every bowl we sell can be read on either reference: the 440 reading is in its name, and the 432 reading is on its page. Gong notes convert the same way. Just as usefully, most of our bowls and gongs are individually recorded, so you can hear the exact instrument before you buy. Browse the Crystal Tones collection or our gongs.