The crystallography of the Cu(100) surface is reexamined by a LEEDI–V profile analysis in order to investigate the effects of applying current experimental and computational techniques. The study produces a very small multi‐beam reliability factor of 0.068, and it is concluded that the first interlayer spacing of Cu(100) is within 2% of the bulk value. The work also demonstrates that agreement between calculational and experimental I–V profiles can be significantly improved by the simple process of data averaging the experimental profiles which should be symmetrically equivalent.