An apparatus for providing a linearity information associated with an amplifier includes an operating state determinator and an evaluator. The operating state determinator is configured to obtain information describing a gain of the amplifier for at least one bias condition of the amplifier. The evaluator is configured to obtain the linearity information based on both the information describing the gain of the amplifier and information about the at least one bias condition of the amplifier using a gain-bias characteristic of the amplifier. A bias circuit including the apparatus for providing the linearity information is also disclosed. A corresponding method for providing the linearity information includes: using the information describing the gain of the amplifier and the information about the at least one bias condition with the gain-bias characteristics to determine a relation of a current operating point described by the information with respect to the gain-bias characteristic; and deriving the linearity information from said relation.