Frequency to Note Converter — Hz to Note, Cents & Tuning Tool

Frequency to Note converter for audio engineers.

Turn any Hz into its musical note — and back — with a live cents meter, harmonic-series explorer, audible reference tones, and the full equal-temperament table. Selectable A4 from 432 to 444 Hz.

Try it here, no account Works offline Built-in reference tones

One page, every pitch answer you need.

Hz ↔ note, cents, harmonics, reference tones, and a searchable note table — all recalculated around the concert pitch you choose.

Hz ↔ note with cents meter

Type any frequency and read the nearest note plus its exact cents deviation on a live tuning gauge. Go the other way too — pick a note and octave, get the precise Hz.

Harmonic series explorer

Enter a fundamental and see its overtones — frequency, nearest note, and cents offset for each harmonic, with a playable tone on every card.

Audible reference tones

Every result plays a clean sine reference straight in the browser. Tune an instrument by ear or A/B two pitches instantly. No plugins, no latency.

Full reference table

The complete equal-temperament chart from C0 to B8 — searchable by note, MIDI number, or frequency, with one-tap playback on every row.

Selectable A4 (432–444 Hz)

Switch concert pitch between 432 and 444 Hz in 2 Hz steps. Every conversion, harmonic, and table value recalculates around your reference.

Browser-native & private

Runs entirely in your browser. No upload, no tracking. Try the demo here with no account; the full tool opens with a free Squaresmile account.

Real interface. Real audio.

These are live pieces of the tool — tap any tone to hear it. Nothing is a screenshot.

01 · Harmonic series of 110 Hz

1st×1

110.00

A2+0¢

2nd×2

220.00

A3+0¢

3rd×3

330.00

E4+2¢

4th×4

440.00

A4+0¢

Each overtone is a whole-number multiple of the fundamental. Note how the 7th harmonic lands noticeably flat of equal temperament — the tool shows you exactly by how much.

02 · Reference table around A4

Note	Oct	MIDI	Frequency (Hz)
G	4	67	392.00
G♯	4	68	415.30
A	4	69	440.00
A♯	4	70	466.16
B	4	71	493.88
C	5	72	523.25
C♯	5	73	554.37
D	5	74	587.33

The full chart runs C0 to B8 and is searchable by note, MIDI, or frequency — with A4 highlighted as your reference row.

Built for working ears.

Tuning & calibration

Dial in analog synths, tape machines, and acoustic instruments against an exact reference tone and cents readout.

432 vs 440 debates

Flip concert pitch and hear the difference for yourself — every note re-derived from your chosen A4.

Mixing & EQ

Find the musical note behind a problem frequency, then notch or boost in tune with the material.

Teaching & theory

Show the harmonic series and equal temperament with audible, interactive examples students can play.

Live sound checks

Confirm a feeding-back frequency's pitch in seconds, on whatever device is in your hand.

Sound design

Build chords and intervals from precise Hz values and preview them without opening a DAW.

From frequency to answer in three taps.

Enter a frequency or note

Type Hz, or pick a note and octave. Everything updates the instant you type.

Read pitch & cents

See the nearest note, exact frequency, MIDI number, and how many cents sharp or flat you are.

Hear it

Tap play for a clean reference tone — then explore harmonics and the full note table.

Frequently asked questions.

What is a frequency-to-note converter?

It's a tool that turns a sound frequency in hertz (Hz) into its closest musical note, and back again. Enter 440 Hz and you'll see it's the note A4; enter a note and you'll get its exact frequency.

What does the cents reading mean?

A cent is 1/100th of a semitone. The gauge shows how far your frequency sits from the nearest in-tune note — under ±5 cents reads as "in tune," anything more is sharp or flat. It's the standard unit for fine tuning.

Why can I change A4 between 432 and 444 Hz?

A4 is the concert-pitch reference the whole scale is built from. 440 Hz is the modern standard, but orchestras and producers use everything from 432 to 444 Hz. Changing it re-derives every note, harmonic, and table value.

Does it work offline and on mobile?

Yes. It's browser-native — once loaded it runs without a connection and works on phones, tablets, and laptops. Reference tones play through the Web Audio API with no plugins or installs.

Is it free?

Yes — Frequency to Note is one of the free tools on Squaresmile Tools. Try the live demo on this page with no account; the full tool opens with a free account — no credit card.

How accurate are the conversions?

Conversions use the standard equal-temperament formula f(n) = A4 · 2^((n−69)/12) with full floating-point precision, and frequencies are shown to four decimal places in the reference table.

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