Piano Frequency Chart: 88 Keys to Hz Converter (A0 - C8)
Interactive piano frequency chart. See the exact Hz value for all 88 keys, from A0 to C8. Learn about concert pitch (A440) and tuning formulas.
The standard modern piano has 88 keys, spanning a frequency range from 27.5 Hz (A0) to 4186 Hz (C8). This interactive chart lets you hear and see the frequency of every note.
Piano Keyboard
Click to play • Double-click to sustain • Shows frequency for each key
The "Standard" Tuning (A4 = 440 Hz)
In modern Western music, pianos are tuned to Equal Temperament with a reference pitch of A4 = 440 Hz.
- Equal Temperament: The octave is divided into 12 mathematically equal semitones.
- A440: The A note above Middle C serves as the universal anchor for tuning orchestras and instruments.
Info
Did you know? Before 1939, tuning standards varied wildly. Mozart tuned to ~421 Hz, while some 19th-century concert halls pushed as high as 450 Hz for "brilliance."
Complete Frequency Table (88 Keys)
Low Range (Sub-Bass & Bass)
The lowest octave (0) is felt more than heard, often functioning as sub-bass rumble.
| Key | Note | Frequency (Hz) | Wavelength (cm) |
|---|---|---|---|
| 1 | A0 | 27.50 | 1255 |
| 4 | C1 | 32.70 | 1055 |
| 16 | C2 | 65.41 | 527 |
| 28 | C3 | 130.81 | 264 |
Mid Range (Speech & Melody)
This is where the human voice and most melodic instruments live.
| Key | Note | Frequency (Hz) | Description |
|---|---|---|---|
| 40 | Middle C (C4) | 261.63 | Central reference point |
| 49 | A4 | 440.00 | Concert Pitch Standard |
| 52 | C5 | 523.25 | "High C" (Tenor/Soprano) |
| 64 | C6 | 1046.50 | Soprano high range |
High Range (Brilliance & Air)
Above C7, notes have very little sustain and sound like short, metallic "pings."
| Key | Note | Frequency (Hz) | Description |
|---|---|---|---|
| 76 | C7 | 2093.00 | Very high |
| 88 | C8 | 4186.01 | Highest note on piano |
The Math: How to Calculate Pitch
Since A4 is defined as 440 Hz, you can calculate any other note using this formula:
f(n) = 440 * 2^(n/12)
Where n is the number of semitones away from A4.
- Octave Up (n=12): 440 * 2^1 = 880 Hz
- Octave Down (n=-12): 440 * 2^-1 = 220 Hz
- Perfect Fifth Up (n=7): 440 * 1.498... = 659.25 Hz (E5)
FAQ
Why do piano tuners "stretch" the tuning?
Real piano strings are stiff, which causes their overtones (harmonics) to be slightly sharp. To make the piano sound in tune with itself, tuners use Stretch Tuning: low notes are tuned slightly flat, and high notes are tuned slightly sharp. The table above shows the theoretical frequencies, but a real concert grand will deviate slightly.
What is the frequency of Middle C?
261.63 Hz. (Specifically C4). Confusion sometimes arises because in MIDI software, Middle C is sometimes labeled C3 (Yamaha standard), but acoustically it is always ~262 Hz.
Can humans hear below A0 (27.5 Hz)?
Yes, the human hearing range extends down to 20 Hz. However, at 27.5 Hz, you need significant volume to hear the tone clearly. On small speakers or phones, A0 is often inaudible or heard only through its harmonics (overtones).
Related Tools:
- Hz to Note Converter - Reverse lookup tool
- Online Tuner - Check your instrument
- Frequency Chart - Visual spectrum guide