The

**cent**is a logarithmic measure of relative pitch or intervals. 1200 cents are equal to one octave, and an equally tempered semitone is equal to 100 cents. The formula to determine the value in cents between two notes with frequencies

*a*and

*b*is:

*On the Sensations of Tone*. It has since become the standard way of measuring intervals in equal temperament systems or for comparison with equal temperament systems.

See also: *music*