Typical bar formation time t_bar as a function of f_disc as defined in Bland-Hawthorn et al. (2023). The dashed lines show the relation given by Fujii et al. (2019). f_disc is derived using the sole stellar disc (right panel) or the total baryonic content (i.e. stars and gas; left panel). In the right panel, f_disc (stars only) decreases when the gas fraction increases as expected (the relative contribution of the stellar disc gets smaller), while in the left panel, f_disc (total) increases with the gas fraction (as the total baryonic contribution increases). As in Fig. 9, the size of each square represents 200 Myr (i.e. ±100 Myr), hence illustrating the uncertainty in t_bar (see Sect. 4.2).