🎹 MIDI Note Frequency Converter
Convert between MIDI note numbers, note names, and frequencies in Hz using equal temperament — with an adjustable A4 reference so you can match any tuning.
🎼 Convert Notes & Frequencies
What is a MIDI Note Frequency Converter?
A MIDI note frequency converter bridges the two ways music software describes pitch: the MIDI note numbers and note names your DAW shows on the piano roll, and the raw frequencies in Hz that synthesizers, filters, and tuners use. Enter one and it returns the others instantly.
With an adjustable A4 reference it adapts to any tuning standard, making it a quick reference for sound design, sampling, tuning hardware, and setting precise filter or oscillator frequencies.
❓ Frequently Asked Questions
How do MIDI note numbers map to frequencies?
Equal temperament splits each octave into twelve equal steps. MIDI note 69 is defined as A4, which is 440 Hz by default. Every step up multiplies the frequency by the twelfth root of two, so the frequency of any note is 440 × 2^((note − 69) / 12). MIDI 60, for example, is C4 at about 261.63 Hz.
What is the A4 tuning reference and why change it?
A4 is the anchor pitch the whole scale is built around — 440 Hz is the modern standard. Some orchestras and producers prefer 442 Hz, or alternative tunings like 432 Hz. Changing the A4 value here recalculates every note so you can match a sample, an old recording, or a specific aesthetic.
Can I convert a frequency back to the nearest note?
Yes. Switch the tool to convert from frequency, enter a value in Hz, and it returns the closest MIDI note number and its name. That's handy for identifying the pitch of a sample, tuning a notch filter to a resonant frequency, or finding the root of a drone.
How do note names and octaves work here?
Names run C, C#, D, D#, E, F, F#, G, G#, A, A#, B, and the octave number comes from the MIDI note: octave = floor(note / 12) − 1. So MIDI 60 is C4 and MIDI 69 is A4, matching the convention used by most DAWs and samplers.