Semitones, Cents & Pitch Ratio Converter
Semitones ↔ cents ↔ frequency ratio ↔ playback speed, interval names and sample-rate pitch shifts
How it works
In equal temperament a semitone is a frequency ratio of 2^(1/12) ≈ 1.0595 and a cent is 2^(1/1200). Enter any one of semitones, cents, ratio or speed percentage and the others follow, along with the interval name, the nearest just-intonation ratio (a perfect fifth is 2 cents narrower than 3:2) and the length change if audio is sped up rather than time-stretched. The sample-rate calculator shows the pitch shift when a file recorded at one rate is played at another.
Questions
How many cents in a semitone?
100 cents. An octave is 1200 cents, or a frequency ratio of exactly 2.
How much does 10% faster playback raise the pitch?
12 × log2(1.10) ≈ 1.65 semitones (165 cents), like an old tape or turntable pitch control.
What happens playing 44.1 kHz audio at 48 kHz?
It runs 8.8% fast and rises 1.47 semitones — the classic accidental sample-rate mismatch.