Precision Determination of the Muon $g_{\mu}-2$ and $\bar{\alpha}_{\rm Q.E.D.}(M^2_{Z})$
We present a summary of the results of two recent precise calculations of the muon anomalous magnetic moment ($g_{\mu}-2$) and the electromagnetic coupling on the $Z$ ($\bar{\alpha}_{\rm Q.E.D.}(M^2_{Z})$). The main sources of uncertainty are underlined.