Standard references show the effects of carrier phase jitter on the performance of digital communications equipment as curves of bit error rate versus signal-to-noise ratio for constant values of jitter variance. In any real system, the variance consists of a relatively small constant component and a component which is inversely proportional to signal-to-noise ratio. This correspondence presents revised calculations of bit error rate for a number of values of the constant variance component and the proportionality constant. The resulting curves are shown to agree with experimental results, and are useful for predicting performance of real systems.