Development of a new chip seal performance indicator called the performance-based uniformity coefficient (PUC) is presented. The PUC uses the concepts of McLeod's failure criteria for chip seals and the uniformity coefficient used for soil, sand, and aggregate. The aggregate loss performance test, using the third-scale model mobile loading simulator, is used for evaluating the PUC. Results demonstrate that the methodology introduced in this research and McLeod's failure criteria can be excellent tools for narrowing the aggregate specifications required for chip seal construction. In addition to these results, the PUC, which is a gradation-based performance indicator, is an improvement over the previous uniformity coefficient for chip seal construction. The PUC can also aid in aggregate selection for the chip seal, and it can ease and clarify engineering communications within the chip seal industry.