The calculation of radar cross section (RCS) of electrically large three-dimensional obstacles is considered. The governing equations are Maxwell’s equations expressed in the conservation form. The solution is obtained by a finite-volume time domain (FVTD) scheme originally developed for solving the compressible Euler equations on the tetrahedral unstructured grid. The computed time domain solution is transformed to frequency domain to determine the bistatic radar cross section of the obstacle. To save computational cost, monostatic radar cross section data are deduced from bistatic results by a monostatic/bistatic approximation technique. The standard sphere test case is used to verify the numerical scheme. The monostatic RCS of EMCC ogive and almond are computed and compared with measurements.