Frequency: -- Hz
This note frequency converter shows the exact pitch in Hz for any note and octave. That's useful for tuning by ear against a reference, understanding harmonics, or setting up electronic instruments and synths precisely.
How to Use
- Pick a note and octave (middle C is C4).
- See the exact pitch in Hz.
- Reference the standard guitar tuning table for quick lookups.
Standard Guitar Tuning (low to high)
| E2 | 82.41 Hz |
| A2 | 110.00 Hz |
| D3 | 146.83 Hz |
| G3 | 196.00 Hz |
| B3 | 246.94 Hz |
| E4 | 329.63 Hz |
Common Reference Pitches
A few fixed points are worth memorizing since so much else is measured against them.
| Note | Frequency | Reference |
|---|---|---|
| C0 | 16.35 Hz | Below the range of most instruments |
| C4 (Middle C) | 261.63 Hz | The most common tuning reference point |
| A4 | 440.00 Hz | International concert pitch standard |
| C8 | 4186.01 Hz | Highest note on a standard 88-key piano |
Did You Know?
Concert pitch A4 is standardized at 440 Hz, though some orchestras tune slightly sharp (442-444 Hz) for a brighter sound. That standard isn't arbitrary: delegates from France, Germany, the Netherlands, Italy, and England agreed on A440 at a 1939 conference in London, and the International Organization for Standardization made it official as ISO 16 in 1975 (source).
Frequently Asked Questions
Does frequency double every octave?
Yes. Moving up one octave doubles the frequency, and moving down one halves it. A4 is 440 Hz, A5 is 880 Hz, and A3 is 220 Hz.
What formula does this converter use?
Standard equal-temperament tuning: frequency equals 440 times 2 raised to the power of (n minus 69) divided by 12, where n is the note's MIDI number. That formula spaces every note evenly on a logarithmic scale.
How is this different from a chromatic tuner app?
A tuner app listens to what you're playing and tells you whether you're sharp or flat. This converter works the other direction: it gives you the exact target frequency for a note first, so you can tune by ear against a reference tone.
Why do some orchestras tune sharp of 440 Hz?
A slightly higher pitch, often 442-444 Hz, is felt to sound brighter and more brilliant, especially in larger halls. It's a stylistic choice some orchestras and countries have settled on rather than a universal rule.