Semitone Calculator

What Is a Semitone?

A semitone, also called a half step, is the smallest interval in twelve-tone equal temperament. On a piano, C to C♯ is one semitone. E to F is also one semitone.

Converting Frequencies to Semitones

In equal temperament, each semitone corresponds to a frequency ratio of $2^{1/12}$. The semitone distance between two frequencies is:

$$n = 12 \times \log_2\left(\frac{f_2}{f_1}\right)$$

One cent equals 1/100 of a semitone, so cents = $100 \times n$.

Frequently Asked Questions

How many cents are in a semitone?

There are 100 cents in one semitone. Twelve semitones span one octave, which equals 1200 cents.

How many cents are between 432 Hz and 440 Hz?

440 Hz is about 31.767 cents above 432 Hz, or roughly 0.32 semitones in equal temperament.

What is the formula for semitones from Hz?

Use n = 12 × log₂(f₂ / f₁). Positive values mean f₂ is higher in pitch than f₁.

What tuning does this calculator use?

It uses twelve-tone equal temperament with A4 = 440 Hz when matching frequencies to note names.

Can I use note names instead of frequencies?

Yes. Switch to note mode and pick two notes with octaves to get the semitone and cent distance between them.

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What Is a Semitone?

Converting Frequencies to Semitones

Frequently Asked Questions

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