Figure shows the microgel equilibrium swelling ratio versus ionization degree for microgels formed by chains of different number of monomers N at constant N cross and N ch . Here, the swelling ration is determined via the microgel radius of gyration R g relative to the radius of gyration from the corresponding neutral case R g (Z = 0). We observe how the swelling ratio increases when increasing the ionization degree ζ = Z/Z max at constant N, with Z max being the charge for which each monomer in the network holds a monovalent charge of -e. Simulations of short-chain microgels depict a mild swelling for growing ionization degree, but flattening at large ionizations. The fact that the chains are short eases configurations with end-to-end distance closer to their contour length R max . As N is enlarged, the swelling becomes more pronounced at low ionization with a likewise flattening for larger ionizations. We also notice that the microgel size increases with increasing N at constant ionization degree as expected. One can see that microgel R g ∝ N δ with δ = 0.57 ± 0.01 for the neutral case, which is close to the expected ν = 0.6 for self avoiding chains; while, δ = 0.94±0.01 for ζ = 0.5, as seen in Fig. , close the expected δ = 1 from scaling theory. The corresponding theoretical predictions are plotted with continuous lines for the Gaussian model and dashed lines for the Langevin model, which are calculated considering a reference collapsed volume such that the monomers in the microgel are arranged occupying a volume fraction of φ coll = 0.22 for all N's. For the shortest chains, N = 10, the mild swelling is well approximated by the Langevin model and overestimated by the Gaussian one at large ζ . With increase of ζ , we observe that both models tend to underestimate the steep swelling at low ζ with a more pronounced effect at larger N. At large ζ , the Gaussian model tends to strongly overestimate swelling, while the Langevin approximately captures the flattening. We see then that Langevin model more accurately describes the swelling ratio in the whole range of charges for a wide variation on chain length.