Music Note Frequencies
Equal-temperament frequencies for every MIDI note.
Overview
The Music Note Frequencies reference lists every MIDI note from 0 to 127 with its scientific pitch notation (C-1 through G9), its equal-tempered frequency in Hertz and its position on the piano keyboard. Tune-up A above middle C is MIDI 69 and lives at exactly 440 Hz, with every other note derived from that anchor by the standard twelfth-root-of-two ratio.
It is for instrument builders calibrating tuning forks, sound designers picking a frequency for a sub-bass, music students learning the relationship between octaves and frequencies and audio engineers debugging a notch-filter that's clipping a snare. Long-tail queries it covers include "frequency of middle C", "MIDI note 60 Hz", "A4 440 vs 432 tuning" and "Hz to musical note converter".
How it works
Equal temperament divides each octave into 12 logarithmically equal semitones. The frequency of note number n is f(n) = 440 × 2^((n − 69) / 12), where 69 is A4 (440 Hz). The exponent of 2 means every octave doubles the frequency: A3 is 220 Hz, A5 is 880 Hz.
The reference computes the frequency for every MIDI note 0 through 127 and tabulates it alongside the note name. The same formula handles fractional MIDI numbers for cents-precise tuning, but the reference table sticks to integer notes. Middle C (C4) is MIDI 60, with a frequency of about 261.63 Hz.
Examples
A4 (MIDI 69) → 440.00 Hz
Middle C (MIDI 60) → 261.63 Hz
A2 (MIDI 45) → 110.00 Hz
A5 (MIDI 81) → 880.00 Hz
FAQ
Why is A4 set to 440 Hz?
The ISO 16 standard fixes concert pitch at 440 Hz, adopted in 1955. Before that orchestras tuned anywhere between 415 and 466 Hz. Some historical and early-music ensembles still use 415 Hz; some "high orchestra" tunings use 442 or 443.
Is 432 Hz tuning meaningfully better?
There's no scientific evidence that 432 Hz has any special acoustic or psychological property. Choose a tuning to match the people you're playing with — that's the only thing that matters in practice.
What's MIDI note 0?
C-1, eight octaves below middle C, at 8.18 Hz. It's below the threshold of human hearing for pitch (about 20 Hz) but is still well-defined as a frequency.
Why does the table go up to MIDI 127?
The MIDI specification uses 7-bit note numbers, giving 0-127. The top note is G9 at 12,543.85 Hz, well above the highest piano note but useful for synthesizers and FM bell tones.
How do cents fit in?
Each semitone is divided into 100 cents. Fractional MIDI numbers (e.g. 69.5) represent 50 cents sharp. The formula still applies: just use a non-integer exponent.