Networks-on-chip (NoCs) are used in a growing number of SoCs and multi-core processors, increasing the need for accurate and efficient modeling to aid the design of these highly-integrated systems. Towards this modeling goal, we present a methodology for packet-level static timing analysis in NoCs. Our methodology enables quick and accurate gauging of the performance parameters of a virtual-channel wormhole NoC without using simulation techniques and supports any topology, link capacities, and buffer depths. It provides per-flow analysis that is orders-of-magnitude faster than simulation while being both significantly more accurate and more complete than prior static modeling techniques. Our methodology is inspired by models of industrial flow-lines. Using a carefully derived and reduced Markov chain, the model can statically represent the dynamic network state and closely estimate the average latency of each flow. Use of the model in a placement optimization problem is shown as an example application of the method.