Intrinsic SFR–L_Hα relation in the SPHINX²⁰ cosmological simulation, color-coded by the stellar metallicity. The SFR values are averaged over t = 10 Myr, i.e., the typical lifetime of stars traced by Hα. The diamonds show the median SFR in the bins of $L_{\mathrm{H}\alpha }^{\mathrm{int}}$, with the error bars showing the standard error on the median. The shaded region indicates the 68% (1σ) confidence interval. The diagonal lines show the SFR(Hα) calibrations from the literature, i.e. (top to bottom), the original K98 calibration, the K98 calibration converted into the Kroupa IMF, and two calibrations from T19 calculated for the Kroupa IMF and two different metallicities (Z_* = Z_⊙ and Z_* = 0.1 Z_⊙, respectively).