Frequency to Note Converter
Convert any frequency in Hz to its nearest musical note with cents sharp or flat. Also convert notes to frequencies. Includes a full reference table from C2 to C6.
Enter a frequency in Hertz
Note
A4
Frequency
440.00 Hz
Exact note frequency: 440.00 Hz
Tuning Offset
Reference Table (C2 - C6)
| Note | Octave | Frequency |
|---|---|---|
| C | 2 | 65.41 Hz |
| C# | 2 | 69.30 Hz |
| D | 2 | 73.42 Hz |
| D# | 2 | 77.78 Hz |
| E | 2 | 82.41 Hz |
| F | 2 | 87.31 Hz |
| F# | 2 | 92.50 Hz |
| G | 2 | 98.00 Hz |
| G# | 2 | 103.83 Hz |
| A | 2 | 110.00 Hz |
| A# | 2 | 116.54 Hz |
| B | 2 | 123.47 Hz |
| C | 3 | 130.81 Hz |
| C# | 3 | 138.59 Hz |
| D | 3 | 146.83 Hz |
| D# | 3 | 155.56 Hz |
| E | 3 | 164.81 Hz |
| F | 3 | 174.61 Hz |
| F# | 3 | 185.00 Hz |
| G | 3 | 196.00 Hz |
| G# | 3 | 207.65 Hz |
| A | 3 | 220.00 Hz |
| A# | 3 | 233.08 Hz |
| B | 3 | 246.94 Hz |
| C | 4 | 261.63 Hz |
| C# | 4 | 277.18 Hz |
| D | 4 | 293.66 Hz |
| D# | 4 | 311.13 Hz |
| E | 4 | 329.63 Hz |
| F | 4 | 349.23 Hz |
| F# | 4 | 369.99 Hz |
| G | 4 | 392.00 Hz |
| G# | 4 | 415.30 Hz |
| A | 4 | 440.00 Hz |
| A# | 4 | 466.16 Hz |
| B | 4 | 493.88 Hz |
| C | 5 | 523.25 Hz |
| C# | 5 | 554.37 Hz |
| D | 5 | 587.33 Hz |
| D# | 5 | 622.25 Hz |
| E | 5 | 659.26 Hz |
| F | 5 | 698.46 Hz |
| F# | 5 | 739.99 Hz |
| G | 5 | 783.99 Hz |
| G# | 5 | 830.61 Hz |
| A | 5 | 880.00 Hz |
| A# | 5 | 932.33 Hz |
| B | 5 | 987.77 Hz |
| C | 6 | 1046.50 Hz |
| C# | 6 | 1108.73 Hz |
| D | 6 | 1174.66 Hz |
| D# | 6 | 1244.51 Hz |
| E | 6 | 1318.51 Hz |
| F | 6 | 1396.91 Hz |
| F# | 6 | 1479.98 Hz |
| G | 6 | 1567.98 Hz |
| G# | 6 | 1661.22 Hz |
| A | 6 | 1760.00 Hz |
| A# | 6 | 1864.66 Hz |
| B | 6 | 1975.53 Hz |
How Musical Notes Map to Frequencies
Each musical note has a specific frequency. The reference is A4 = 440 Hz (concert pitch, standardised in 1955). Each octave doubles the frequency: A3 = 220 Hz, A5 = 880 Hz. Each semitone is a factor of the 12th root of 2 (≈1.0595). So A4 to A#4: 440 × 1.0595 = 466 Hz.
Useful for instrument tuning, sound design, audio engineering, and music theory analysis. Middle C (C4) = 261.63 Hz. The lowest E on a standard tuned guitar (E2) = 82.41 Hz. The highest E on a piano (C8) = 4186 Hz. Concert tuning hovers around A4 = 440 Hz; orchestras sometimes tune slightly higher (442-444 Hz) for brightness.
Common Note Frequencies
| Note | Frequency (Hz) |
|---|---|
| A0 (lowest piano) | 27.50 |
| E2 (low E guitar) | 82.41 |
| A2 | 110.00 |
| A3 | 220.00 |
| C4 (middle C) | 261.63 |
| A4 (concert pitch) | 440.00 |
| A5 | 880.00 |
| C8 (highest piano) | 4186.01 |
Frequently Asked Questions
Why is concert pitch 440 Hz?
International agreement in 1955 (ISO 16) set A = 440 Hz as the global standard. Before that, orchestras used 415-450 Hz variously. The 440 Hz value was a compromise between bright (higher) and dark (lower) preferences across European orchestral traditions.
Can I tune to a different reference?
Yes. Some performers use A = 432 Hz (claimed esoteric 'natural tuning'). Some baroque ensembles use A = 415 Hz (lower, period-authentic). Some jazz musicians tune slightly sharp. The note ratios (octaves, fifths, thirds) remain mathematically identical regardless of reference.
Related Tools
Guitar Tuner
Free online guitar tuning reference with 11 alternate tunings. Hear the correct pitch for each string, see the notes on an interactive fretboard and tune by ear.
Music Theory Reference
Interactive music theory reference with a circle of fifths, interval chart and chord construction guide. Learn keys, scales and how chords are built.
Online Metronome
Free online metronome with tap tempo, multiple time signatures, subdivisions and a speed trainer. Visual pendulum, precise Web Audio timing and tempo presets.