One important issue in phase-shifting interferometry is to eliminate or compensate for phase shift errors. One solution is to adopt a least-squares technique in that actual reference values of phase shifts are readily identified directly from interferograms. This however, requires a relatively long computation time since a considerable amount of intensity information must be processed in an iterative way. To cope with this problem, we present an accelerated version of a least-squares phase-measuring algorithm that can drastically reduce computation time. © 1997 Society of Photo-Optical Instrumentation Engineers.