01
One semitone contains 100 cents
In twelve-tone equal temperament, an octave contains 1,200 cents and each semitone contains 100. A value of 0 cents means the detected pitch matches the selected target; a negative value is flat and a positive value is sharp.
The scale is logarithmic because musical intervals depend on frequency ratios. The same cents difference represents the same interval at D3 and D4 even though the numerical difference in hertz is larger in the higher octave.
- cents
The detected frequency is below the target frequency, so the display reads flat.
0 cents
The detected and target frequencies match at that measured moment.
+ cents
The detected frequency is above the target frequency, so the display reads sharp.
02
How a tuner calculates the value
A pitch detector first estimates frequency and chooses a target note. The difference can then be expressed as 1,200 × log2(detected frequency / target frequency). This is why changing the A4 reference changes the target frequency and therefore changes the cents result.
Cents should be read together with the detected note and frequency. If the detector briefly follows an octave or fifth resonance instead of the fundamental, the number may be mathematically correct for the wrong component of the sound.
03
Prefer a stable range over a perfect instant
A handpan strike begins with a noisy transient and then settles into several interacting resonances. The display may move during that process. Wait for stable frames, repeat the strike and compare the cleanest readings rather than chasing a momentary zero.
A cents value alone cannot determine whether an instrument needs repair. Professional assessment also considers octave and fifth tuning, beating, sustain, tone-field stability and interaction across the shell.
Try a measured check
Open the handpan tuner
Play one note at a time and wait for a stable reading.