Note Frequency Chart
A configurable chart of musical note frequencies in equal temperament, with adjustable A4 reference and a play button for every note.
๐ Runs entirely in your browser โ nothing is uploadedA complete map of note frequencies
This chart lists every musical note alongside its pitch in hertz, the unit that measures how many times per second a sound wave vibrates. The names use scientific pitch notation, which combines a note letter with an octave number โ for example A4 is the A above middle C and sits at 440 Hz by default. Each octave doubles the frequency: A3 is 220 Hz, A4 is 440 Hz and A5 is 880 Hz. Use the table to look up a target pitch for tuning, programming a synthesiser, writing a part for an instrument, or simply understanding how the notes you play relate to physical frequencies.
Press the play button on any row to hear that note generated as a clean tone, so you can match it by ear or confirm a tuning. You can narrow the table to a smaller octave range when you only care about the singing or playing range of a particular instrument, or expand it to the full piano-and-beyond span from octave 0 to 8.
How equal temperament works
Western music almost always uses twelve-tone equal temperament, where the octave is divided into twelve equal semitones. Mathematically, moving up one semitone multiplies the frequency by the twelfth root of two, roughly 1.0595. Starting from the A4 reference, the frequency of any note is A4 ร 2^(n / 12), where n counts semitones above (positive) or below (negative) A4. Because every step uses the same ratio, music sounds equally in tune in any key, which is why this system became the standard for pianos, guitars and digital instruments alike.
Changing the tuning reference
The A4 box lets you retune the entire chart. The global standard is 440 Hz, but it is not universal: many orchestras tune slightly higher to 442 or 443 Hz for extra brilliance, while historically informed baroque ensembles often drop to 415 Hz, about a semitone lower. Enter any value and every frequency in the table โ and the pitches you play โ recalculates instantly. All of this runs locally with the Web Audio API, so the tool is private, free and works without an internet connection once loaded.
How to use
- Set the A4 referenceKeep 440 Hz for standard concert pitch or change it to match an ensemble.
- Find your noteScroll the table to the note and octave you need and read its frequency.
- Play itPress the play button on any row to hear that exact pitch.