Rest-MIR size–mass (upper panels) and rest-optical size–mass (lower panels) distributions of the 69 SFGs in our final sample. Circles are color-coded by the distance of each galaxy to the MS, i.e., −0.5 < ΔMS < 0.5 (orange), and ΔMS > 0.5 (brown). Circles outlined by black edges are detected in the FIR by Herschel. The rest-MIR sizes were inferred by setting n_MIR = 1 during our partial structural parameter analysis. Black dots show galaxies within the four CEERS red MIRI fields but which remained undetected in a MIRI bandpass that is dominated by dust emission (i.e., S/N < 10 or ). Open diamonds and squares show the 16th, 50th, and 84th percentiles of the rest-MIR and rest-optical size distributions in bins of stellar mass, respectively. Squares (rest-optical sizes) are reproduced in the upper panels for comparison to the rest-MIR sizes and have been shifted by 0.1 dex along the x-axis for clarity. The blue- and red-shaded regions correspond to the size–mass relation inferred in the rest-optical by van der Wel et al. (2014) for late-type and early-type galaxies, respectively. The green-shaded region shows the size–mass relation inferred in the submm by Gómez-Guijarro et al. (2022a) using mostly massive (∼10^10.8 M_⊙) and high-redshift (z ∼ 2.5) SFGs. Here, we assumed a mean axis ratio of 0.5 (see Fig. 7) to convert their circularized radii into semi-major axis radii. Vertical dotted lines show the mass completeness limits of our sample. Typical 1σ error bars for individual objects are shown in the upper and lower right panels.