Exact Hz for every musical note — full piano range
| Note | Freq (Hz) | MIDI | Wavelength | Enharmonic |
|---|
Sound is vibration — a note's pitch is determined by how many times per second the air pressure oscillates, measured in Hertz (Hz). Higher frequencies sound higher in pitch. The relationship between pitch and frequency in Western music is based on equal temperament, where the octave is divided into 12 equal semitones.
The key mathematical relationship is that each octave doubles the frequency. A4 is 440 Hz, A5 is 880 Hz, A3 is 220 Hz. Between each pair of adjacent octaves, the 12 semitones are evenly distributed on a logarithmic scale — each semitone multiplies the frequency by the 12th root of 2, approximately 1.05946.
The formula is: f = A4 × 2^((n − 69) / 12) where n is the MIDI note number. This calculator uses that formula with your chosen reference pitch, so you can calculate frequencies for any tuning standard.
440 Hz has not always been the standard. Concert pitch has varied significantly across centuries and regions — sometimes by more than a semitone. This matters when performing or recording historical music, or when transcribing recordings made under different tuning conventions.
| Standard | A4 pitch | Era / context |
|---|---|---|
| Baroque pitch | 415 Hz | Common in Baroque music performance (~1 semitone below modern) |
| Classical pitch | 430 Hz | Used in some early Classical era orchestras |
| 432 Hz | 432 Hz | Preferred by some modern musicians; claimed to sound "warmer" |
| ISO 16 / Standard | 440 Hz | International standard since 1955; used by most orchestras |
| High orchestral | 442–444 Hz | Used by some European orchestras for brighter sound |
| Scientific pitch | 430.54 Hz | Places C4 at exactly 256 Hz; used in some scientific contexts |
Use the reference pitch input above to calculate frequencies at any of these standards. The cents deviation from 440 Hz is shown next to the frequency.
Select a note and octave, set your reference pitch (default A4 = 440 Hz), and see the exact frequency with MIDI number, wavelength, and cents deviation. The octave strip shows the same note across all piano octaves. The frequency table covers all 88 piano keys with optional instrument range highlighting. Export as CSV for use in tuning documentation or analysis.