The decays W → ev and Z → e+e- are studied in [ovbar|p]p collisions at √s=630 GeV. The products of production cross section and branching ratio are measured as σe w=682±12±40 pb and σe w=65.6±4.0±3.8 pb. The results are in good agreement with O(α2 s) calculations of the production cross sections. Many systematic effects cancel in the ratio, R=10.4±0.7 0.6±0.3, which can be used to give an indirect measurement of the total width of the W boson: Γw=2.10±0.13±0.09 GeV. The width gives a limit on the top quark mass, mtop>53 GeV (95% CL), which is independent of the top decay mode.