The power in a PRBS NRZ signal is expressed as a sinc squared function of the independent variable x. In order to calculate the power in this signal from 0 to some arbitrary x a definite integral of the sinc squared function has to be found. This is not an easy task. Having searched the web for ready solutions of this problem very few relevant references were found. Therefore a technique was evolved from series expansions of the sinc and sinc squared functions. The accuracy of the estimates found by using this technique is completely dependent on the engineer. We found that using just four or five terms in the expansion allowed us to calculate to within accuracies of interest to us. The technical report can be found in the engineer’s corner in the SPG website located at http://www.signalpro.biz.