# equivalent noise resistance (ENR)

Equivalent Noise Resistor (ENR) is a quantifiable resistance value that corresponds to the spectral density of a noise generator.

Equivalent Noise Resistance is a relative quantity used as a comparison value with the noise of a resistor. Each resistor produces a thermal noise voltage that is a function of the spectral density, Boltzmann constant, and absolute temperature in Kelvin. The ENR value is given in ohms and is calculated as `pi` times the spectral density in relation to the Boltzmann constant multiplied by the absolute temperature.