CERN-LHC, ATLAS. Measurements of the fiducial and total cross sections and ratios for W+/-, Z production using the electron and muon final states in proton-proton collisions at a centre-of-mass energy of 13 TeV with 81 pb^-1 of data collected in 2015. Where there are two systematic uncertainties, the first is experimental (omitting luminosity) and the second uncertainty is that of luminosity. ; Other ; Measured total cross section times leptonic branching ratio for W- production in the combined W- -> l- nubar (l = e, mu) final state.