Accurate estimation of power in pre-silicon is very important and finally to validate this against post-silicon measurement is essential throughout product lifecycle. Thermal Design Power (TDP)1 estimates are used to design package thermal solutions. In this paper a modeling approach for dynamic power estimation under TDP conditions is proposed. In this approach, separate models are built for each partition in the design. The model uses only bandwidth and the effective toggle rate of the input data for estimating the total switched capacitance and dynamic power. The model takes into account the effect of cross-coupling capacitance on dynamic power. The results obtained from the model are within 7% of the measured data.