Note Frequency Calculator

What This Calculator Does

This tool finds the exact frequency, in hertz, of any musical note and octave using standard 12-tone equal temperament tuning — the system used to tune nearly all modern Western instruments, from pianos to guitars to synthesizers.

The Formula

Equal temperament divides each octave into 12 equal semitone steps. The frequency of any note is calculated as f = reference pitch × 2^(n/12), where n is the number of semitones the note is above or below the reference note, A4 (usually tuned to 440 Hz). Each octave up doubles the frequency, and each octave down halves it.

A Few Notes

• Octave numbers follow scientific pitch notation, where middle C is C4.
• Some orchestras and historical tunings use a different A4 reference pitch (such as 442 Hz) — adjust the reference field to match.
• Provided for general music theory and educational purposes.