How is the dielectric constant of a material calculated?

The dielectric constant of a material is calculated by comparing the capacitance of a capacitor when it is in a vacuum to the capacitance when it is filled with the material in question. This comparison allows for the determination of how much more effectively the material can store electrical energy compared to a vacuum.

In a capacitor, the presence of a dielectric material affects the electric field and thus influences the capacitance. The dielectric constant is defined as the ratio of the capacitance with the dielectric to the capacitance without it (in a vacuum). This understanding stems from the material's ability to polarize in response to an electric field, which enhances the capacitor's ability to store energy.

Other approaches, such as measuring thermal conductivity or electrical resistance, do not provide direct insight into a material's ability to store electrical energy and therefore do not relate to the dielectric constant.