A design tool with an initial sink locator unit determines a number of clock buffers for driving clock signals to loads in a clock distribution network. The design tool determines clusters of loads in the clock distribution network, wherein the number of clusters is equal to the number of clock buffers and the loads are uniformly distributed amongst the clusters. The design tool determines centers of the clusters as initial candidate sink locations for the clock buffers. The design tool iteratively determines new clusters and determines centers of the new clusters as optimized initial candidate sink locations.