A hybrid FPGA consists of island-style fine-grained units and domain-specific coarse-grained units. This paper describes an approach to estimate the power consumption of a set of hybrid FPGA architectures. The dynamic power consumption of the fine-grained units is obtained using standard FPGA tools, and the coarse-grained units using standard ASIC tools. Based on this approach, the dynamic power consumption of different hybrid FPGA architectures can be studied and we report on results over a set of floating point benchmark circuits.