Work out instrument tuning frequency instantly with clear inputs, formula shown and shareable results.
Equal temperament sets frequency as the reference pitch times two to the power of total cents over twelve hundred, where each semitone is exactly one hundred cents. A five cent offset is about the smallest most listeners notice on a sustained note, which is why tuners are calibrated in cents rather than hertz.
Frequency
f = A4 x 2 ^ ((semitones x 100 + cents) / 1200)
Wavelength
wavelength = speed of sound / frequency, taking 343 m/s at 20 C
f = A4 x 2 ^ ((semitones x 100 + cents) / 1200). Equal temperament sets frequency as the reference pitch times two to the power of total cents over twelve hundred, where each semitone is exactly one hundred cents.
A five cent offset is about the smallest most listeners notice on a sustained note, which is why tuners are calibrated in cents rather than hertz.
Enter semitones from a4, reference pitch for a4, cents offset. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.