440 Hz — Nearest Note: A4
440 Hz is closest to A4 in equal temperament at A=440 Hz. The deviation is 0.00 cents (exactly on the nearest equal-tempered pitch).
440 Hz is the ISO 16:1975 international concert pitch standard. It is the reference frequency used to define equal temperament — A4 is exactly 440 Hz by definition at this standard.
Multi-Temperament Context for A4
The table below shows how A4 is tuned in all 16 temperaments at A=440 Hz, and how far 440 Hz falls from each.
| Temperament | Hz (A=440) | vs Equal Temp (cents) | Distance from 440 Hz (cents) |
|---|---|---|---|
| Equal Temperament | 440.000 Hz | 0.00 | 0.00 |
| Pythagorean | 440.000 Hz | 0.00 | 0.00 |
| Just Intonation (Major) | 436.043 Hz | -15.64 | +15.64 |
| Just Intonation (Minor) | 436.043 Hz | -15.64 | +15.64 |
| Quarter-Comma Meantone | 440.000 Hz | 0.00 | 0.00 |
| Third-Comma Meantone | 440.000 Hz | 0.00 | 0.00 |
| Sixth-Comma Meantone | 440.000 Hz | 0.00 | 0.00 |
| Werckmeister III | 440.000 Hz | 0.00 | 0.00 |
| Werckmeister IV | 440.000 Hz | 0.00 | 0.00 |
| Werckmeister V | 440.000 Hz | 0.00 | 0.00 |
| Kirnberger III | 440.000 Hz | 0.00 | 0.00 |
| Vallotti | 440.000 Hz | 0.00 | 0.00 |
| Young (1799) | 440.000 Hz | 0.00 | 0.00 |
| Bach/Lehman | 440.000 Hz | 0.00 | 0.00 |
| Neidhardt | 440.000 Hz | 0.00 | 0.00 |
| Kellner (Bach) | 440.000 Hz | 0.00 | 0.00 |
Positive cents = 440 Hz is sharp of the temperament pitch. Negative = flat. The "Distance from 440 Hz" column answers: in which temperament does 440 Hz come closest to A4?
Chromatic Neighbors
The notes immediately below and above A4 on the chromatic scale (in equal temperament at A=440 Hz):
See full frequency data for A4.
Adjacent Frequencies in This Index
Other commonly-searched frequencies near 440 Hz:
Instruments That Play A4
A4 (440.000 Hz) falls within the comfortable playing range of 46 instruments.
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