Flowfield solutions of a projectile with wraparound fins have been computed in a supersonic region with a time-marching, three-dimensional Euler equation. The roll moment coefficients were computed from the flow-field solution and compared with the experimental results. The roll moment coefficient computations show good agreement with the experimental measurements for various Eight Mach numbers. This shows that the Euler equations can give comparably accurate solutions when computing the roll moment of wraparound fin configurations. Comparing the flowfield solutions before and after the roll reversal, the roll reversal at higher Mach number than Mach 1 is thought to be due to the effect of a compression/expansion wave from a neighboring fin. Through the comparison with the previous results, it is shown that the tip shape, as well as the edge shape, has a significant effect on the roll moment of the wraparound fin.