Precision SUSY measurements at CERN LHC

If supersymmetry exists at the electroweak scale, then it should be discovered at the CERN Large Hadron Collider (LHC). Determining masses of supersymmetric particles, however, is more difficult. In this paper, methods are discussed to determine combinations of masses and of branching ratios precisely from experimentally observable distributions. In many cases such measurements alone can greatly constrain the particular supersymmetric model and determine its parameters with an accuracy of a few percent. Most of the results shown correspond to one year of running at LHC at ``low luminosity,'' ${10}^{33}{\mathrm{cm}}^{\mathrm{\ensuremath{-}}2}{\mathrm{s}}^{\mathrm{\ensuremath{-}}1}.$