What is equal temperament?

Equal temperament divides an octave into 12 equal semitones. Each semitone is a frequency ratio of 2^(1/12) ≈ 1.05946. This lets instruments play in any key without retuning, at the cost of slight deviations from pure harmonic ratios.

Why do some people prefer 432 Hz over 440 Hz?

A4 = 440 Hz has been the international standard since 1955. Some musicians prefer 432 Hz claiming it sounds warmer or more natural, though no peer-reviewed acoustic research confirms a perceptual advantage. This calculator lets you compare both.

How is each note frequency calculated?

The formula is f = A4_ref × 2^((midi − 69) / 12), where midi is the MIDI note number (A4 = 69, C4 = 60, etc.). Changing the A4 reference scales all other notes proportionally.

What range of A4 values can I enter?

The tool accepts values from 400 Hz to 480 Hz. Standard concert pitch is 440 Hz; common alternates are 432 Hz, 444 Hz, and 415 Hz (Baroque pitch).

How do I copy a frequency value?

Click any frequency cell in the table to copy the value to your clipboard. A brief highlight confirms the copy.

Tuning Frequency Calculator

Name: Tuning Frequency Calculator
Availability: InStock
Author: Nham Vu

Enter a reference pitch for A4 (default 440 Hz) and see the frequency of every note across all octaves in equal temperament.

Reference Pitch

A4 Frequency (Hz)

Quick Presets

A4 (Reference)

440.00 Hz

Formula: f = A4 × 2^((n−69)/12) where n is the MIDI note number.

Note Frequencies (Hz)

Click any cell to copy

Note	0	1	2	3	4	5	6	7	8

C4 (Middle C)

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A4 (Reference)

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A5 (Octave up)

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Summary

Enter a reference pitch for A4 (default 440 Hz) and see the frequency of every note across all octaves in equal temperament.

How it works

Enter the A4 reference frequency (default 440 Hz) in the input field.
The tool applies the equal temperament formula: f = A4 × 2^((n−69)/12) for each MIDI note number n.
Every chromatic note (C through B) is computed for octaves 0 through 8.
The note table updates immediately — no submit button needed.
Click any frequency cell to copy it to your clipboard.
Use the preset buttons to switch quickly between common reference pitches.

Use cases

Tune a synthesizer to 432 Hz to match an ensemble playing at that reference.
Verify that a digital instrument is exactly on concert pitch (A4 = 440 Hz).
Find the precise frequency of a specific note for use in a tone generator or oscillator.
Compare 440 Hz and 432 Hz tables side-by-side to understand how much each note shifts.
Generate reference frequencies for calibrating guitar tuners, strobe tuners, or DAW plugins.
Teach students how equal temperament divides the octave into 12 equal semitone ratios.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu