A recent study demonstrated that solute hydrogen (H) increases both strength and ductility in some Fe-Cr-Ni-based austenitic alloys with high phase stability of austenite. The more solute H content, this novel impact, which solute H improves the strength-ductility balance, becomes pronounced. The amount of solute H depends on the content of Cr and Ni of Fe-Cr-Ni-based austenitic alloys. The larger the Cr content and the higher Cr, Ni ratio, the more solute H is retained in these alloys. However, the quantitative understanding of the contributions of Cr and Ni to the solute H content of the Fe-Cr-Ni-based austenitic alloys still lacks for utilizing H as a beneficial alloying element. In this study, we evaluated these contributions based on the calculation of the hydrogen absorption energy (H-absorption energy), which was the energy required to solidify H in a Fe-Cr-Ni atomic system, at interstitial positions in the vicinity of Cr or Ni atoms using DFT calculations.