Abstract <p>High-entropy alloys (HEAs) have attracted significant interest due to their unique properties. Extensive studies have been conducted on HEAs based on 3<i>d</i> transition metals, refractory metals, rare-earth elements, light metals, high-entropy metallic glasses, and ceramic HEAs such as oxides, carbides, borides, and nitrides. A separate category includes alloys composed of low-melting-point elements, the main properties of which are fatigue resistance, plasticity, and adhesion to other metallic materials. The choice of HEA compositions is determined by numerous factors, the most critical of which are related to the operating conditions of materials. To predict the possibility of formation of disordered solid solutions based on a certain crystal lattice and intermetallic (IM) phases in multicomponent alloys, researchers most often use several key parameters (criteria), such as mixing enthalpy (Δ<i>H</i>_m), atomic size difference (δ<i>r</i>), generalized thermodynamic parameter (Ω), valence electron concentration (VEC), and electronegativity. At present, there is no single universal parameter or specific combination of parameters that can accurately predict the formation of both disordered solid solutions based on a certain crystal lattice and intermetallic phases in multicomponent alloys. In this work, we review the criteria and parameters used to estimate the potential formation of HEAs and describe the software tools fused to calculate them.</p>