AbraCalc

24 Semitones (Two Octaves) Frequency Ratio

Twenty-four semitones span two octaves, giving a frequency ratio of exactly 4.0.

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How to use this tool

  1. Enter semitones in the fields above.
  2. Results update instantly as you type — or click Calculate.
  3. Read your frequency ratio and the full breakdown beneath it.

Two octaves up means the frequency is multiplied by 4, equivalent to 24 semitone steps in equal temperament.

Frequently asked questions

What is the frequency ratio of an octave?
An octave is exactly 12 semitones, corresponding to a frequency ratio of 2:1.
What is the perfect fifth ratio?
A perfect fifth is 7 semitones; the equal-temperament ratio is 2^(7/12) ≈ 1.4983.