Scale-independent calculation of sin2θefflept

We present a calculation of the electroweak mixing parameter sin2θefflept that incorporates known higher order effects, shares the desirable convergence properties of the MS scheme, and has the important theoretical advantage of being strictly independent of the electroweak scale in finite orders of perturbation theory. We also show how this formulation can be extended to the calculation of the W mass MW. The results provide accurate, scale-independent evaluations of these important parameters, as functions of the Higgs boson mass MH, and are compared with previous calculations in order to analyze the scheme and scale dependence of the electroweak corrections.