Here, we presented the dataset and the procedure for obtaining scale factors for the IR vibrational spectra. We developed two sets of scale factors, derived from two different principles: absolute scaling (s abs ), by taking into account absolute deviations of the theoretical frequency from the experimental ones, and relative scaling (s rel ), which minimizes the relative deviation of one frequency from another. The numerical demonstrations with three molecular systems of various sizes (pyrene and two ionic peptides: protonated LeuEnk and doubly protonated gramicidin S) show that the s abs provides better results for the hydrogen-stretching region (above 2000 cm -1 ), whether the s rel outperforms s abs in the fingerprint region (below 2000 cm -1 ). Thus, we recommend joint usage of these scale factors to improve the predictions for different spectral regions. The RMSD values accompanying these scale factors can be used to know the appropriate deviation of the observable band positions from the scaled harmonic frequencies at a given level of theory. These considerations should always be taken into account whenever the experimental data is interpreted.