OhMyCalc

Frequency to Note Calculator

Convert a sound frequency in Hz to the nearest musical note, octave, and cents offset.

How to Use the Frequency to Note Calculator

  1. Enter the frequency in Hz (e.g. 440 for A4).
  2. Click Calculate to see the musical note and octave.
  3. Check the cents offset to see how in-tune the frequency is.
  4. Use the nearest note frequency for precise tuning reference.

Use Cases

Formula

n = 12 × log₂(f / 440) + 69. Note = n mod 12. Octave = floor(n / 12) − 1. Cents offset = (n − round(n)) × 100.

Frequently Asked Questions

What is A440?
A440 is the standard concert pitch where the A above middle C is tuned to 440 Hz.
What are cents?
Cents measure the difference between two frequencies. 100 cents = 1 semitone. Positive cents = sharp, negative = flat.
Is it free?
Yes, all calculators on OhMyCalc are completely free.