Wolfram|Alpha has octahedron surface area calculators. Solve surface area problems related to regular octahedra; first octahedron 3‐, 4‐, 5‐ or 10‐compounds; second octahedron 4‐compounds; equilateral hexagonal prisms; small triakis octahedra; stellated octahedra; first and second tetrahedron 2‐compounds; canonical 4‐trapezohedra; triangular cupolas; tridiminished icosahedra; truncated octahedra; and truncated tetrahedra.
