The paper presents the algorithms for sample mean and dispersion of peak-to-average-power-ratio (PAPR) of multicarrier signals with orthogonal (OFDM-signals) and non-orthogonal (SEFDM-signals) multiplexing. The simulation results are also presented for some subcarriers and modulation types. It is shown that the PAPR calculated over the signal samples on the basic sampling frequency differs greatly from the PAPR calculated over the equivalent continuous signal. The accuracy of the calculated sample mean and dispersion of PAPR depends on the sample size and on the oversampling rate. Simulation results are proposed for the sample sizes and oversampling rates for which further increase in computation complexity does not affect the sample mean and dispersion of PAPR. The proposed algorithms are applicable for any number of subcarriers in the multicarrier signal.