%/°C

percent per Celsius degree

Thermal expansion coefficientexact by definition

The percent per Celsius degree is 0.01 /K exactly. It is the standard form for temperature coefficients that are large enough to be inconvenient in ppm: the volumetric expansion of a hydraulic oil is about 0.07 %/°C, and the temperature coefficient of a silicon solar cell's output is around −0.4 %/°C.

Watch out: A percent-per-degree coefficient describes a fractional change, so it compounds over a wide temperature span rather than adding. Over a few tens of degrees the difference is negligible; over hundreds it is not.

1 %/°C 0.01 1/K