Semitone Frequency Transpose Calculator

It multiplies the starting frequency by the pitch ratio 2^(semitones / 12). In equal temperament each semitone is the twelfth root of two, so twelve semitones double the frequency and minus twelve halve it.

One semitone has a ratio of 2^(1/12), about 1.059463. Shifting up by a semitone multiplies the frequency by that value, and shifting down divides by it.

Yes. Enter a negative number of semitones. Moving down twelve semitones gives a ratio of 0.5, so 440 Hz becomes 220 Hz one octave lower.

In equal temperament a fifth is seven semitones, a ratio of about 1.498307, slightly narrower than the 1.5 of just intonation. That small compromise lets every key sound equally in tune.

No. Any positive frequency works, so you can transpose a raw sample, an oscillator pitch or even a filter cutoff by a musical interval and read the exact target frequency.

Every twelve semitones is one octave and doubles the frequency, a ratio of 2. Going down an octave halves it, a ratio of 0.5. Two octaves up is a ratio of 4, and so on in powers of two.

Yes. The formula accepts any real number, so 0.5 semitones is a quarter tone and 0.01 is a fine tuning nudge. This is handy for microtonal work or for matching a slightly detuned recording.

One semitone is exactly 100 cents, so 50 cents equals 0.5 semitones here. If you know a shift in cents, divide by 100 to get the semitone value to enter, or use a dedicated cents calculator.

The frequency and ratio are rounded to six decimal places, which is far finer than the ear can hear. Everything is computed in your browser with no upload, so nothing you enter leaves your device.