However, interpreting the IR and other vibrational spectra can be complicated. Despite the existence of various vibrational diagnostic bands for molecular functional groups and databases of the experimental IR spectra, such as the NIST Chemistry WebBook, most experimental studies of novel uncharacterized substances have to rely on quantum-chemical calculations. To achieve a sufficiently good agreement of quantumchemical calculations and experiment requires the application of expensive computational methods and direct inclusion of anharmonic effects. Unfortunately, such anharmonic calculations require significant expertise and computational efforts, which make them unfeasible for many practical cases. Therefore, the most widely used computational approach for the interpretation of experimental spectra is the harmonic frequency calculation with subsequent scaling of the resulting frequencies with a pre-defined global scale factor. The scale factor accounts for two effects: 1) the quality of the quantum-chemical approximation used and 2) anharmonic effects, which are, by definition, absent in the harmonic calculations. Therefore, updating the sets of scale factors, considering the expanding corpus of the experimentally determined vibrational frequencies and the new quantum-chemical methods, is an interminable task. This effort is further facilitated by dedicated groups of researchers who diligently monitor and periodically incorporate new updates into these databases to ensure that the scale factors remain current and reflect the latest advances in the field. This work presents a new set of scale factors for the 27 quantum-chemical methods. In addition, these new scale factors have been rigorously tested and compared on several experimental data for structures to ensure their accuracy and reliability. The comprehensive examination of these scale factors across various classes of molecules enhances our understanding of their applicability and underscores their potential to advance computational chemistry methodology.