${\displaystyle TC\epsilon =\frac{{\epsilon }_T–{\epsilon }_{\text{ref}}}{{\epsilon }_{\text{ref}}\left(T–T_{\text{ref}}\right)}}$

where

ε_T is the permittivity at temperature T;

ε_ref is the permittivity at reference temperature T_ref

Note 1 to entry: The temperature coefficient of permittivity is generally expressed in megakelvins to the power minus one (1/MK).