With the high integrated luminosities recorded at the LHC and the very good understanding of the LHC detectors, it is possible to measure electroweak observables to the highest precision. In this talk, I review the measurement of the W boson mass as well as the measurement of the electroweak mixing angle with the ATLAS detector, both achieving highest precision after several years of intense effort. Special focus is drawn on a discussion of the modeling uncertainties as well as the physics potential of the latest low-mu runs, recorded at in 2017 and 2018. The results will be interpreted in terms of the overall consistency of the Standard Modell by the global electroweak fit, performed by the Gfitter Collaboration.