Precise tracking of frequency is essential for accurate phasor estimation at off nominal frequencies. In this paper, a simple approach for real time frequency estimation involving interpolation of DFT coefficients corresponding to fundamental and two adjacent bins is presented. In particular, quadratic interpolation method is adopted to estimate the frequency. The quadratic interpolation formulation widely adopted in signal processing framework may not be adequate for frequency estimation of power system signals. The modifications required to improve the accuracy are presented. Results on standard test signals and simulated waveforms of practical equivalent systems of Indian grid are presented to validate the proposed approach. © 2016 IEEE.