Power cables are one of the major components of a power distribution system, and a failure occurring in the cables will directly affect the operation of the distribution system. Hence it becomes imperative to make an assessment of the condition of the power cable and to make an estimate of the residual life of the cable. The failure of power cables is mainly attributed to the failure of the cable insulation which is the weakest part of a cable. The insulation fails primarily due to aging and the aging in cable insulation can be due to multiple reasons which includes thermal stress, electrical stress, mechanical stress and other environmental as well as operating conditions acting over a long duration of time. In this work, we use the Arrhenius equation to predict the aging of the electrical insulation in power cables. The original Arrhenius equation gives a constant which represents the reaction rate of the chemical process that is causing the degradation of the insulation material. We use a different form of the Arrhenius equation to estimate the life of cables. The simulations and calculations done in MATLAB suggest that this method of estimating cable life gives realistic estimates and can be used for cable life assessment.