Many applications, such as video streaming, congestion control, and server selection, can benefit when the data rate of different priority groups between two endpoints is accurately estimated over the end-to-end path. With the introduction of programmable networks, e.g., P4, it is now possible to offload the measurements to the data plane of intermediate devices. Recently, tools have been developed to react to changes in available bandwidth, but a tool to accurately estimate end-to-end per-priority data rates needs to be added. This motivates us to design and implement a new end-to-end and per-priority data rate estimation tool, PrioMeter. PrioMeter can accurately report the data rate per priority group of flows in programmable networks using high-precision timestamps for arbitrary traffic scales. PrioMeter leverages two primitives: quantization and truncation, to achieve its goals. We implement PrioMeter in P4 and test it on BMv2 switches, and our preliminary results using NS3 simulations show that it can accurately estimate the data rate of different priority flows with minimal overhead.