Ratio of the mass predicted by the neural network models to the real mass enclosed within different radii of the galaxies in the test sets of NIHAO and AURIGA galaxy projections. The coloured lines show the median ratio using the mass estimated by the CNN for the training set, while the shaded regions indicate the 1σ errorbars. Purple: Results of the StarGas model trained on NIHAO galaxies. Pink: Results of the StarGas model trained on AURIGA galaxies. Orange: Results of the StarGas model trained on both simulation suites. The predicted-to-true enclosed mass ratios resulting from applying literature mass estimators to both NIHAO (left) and AURIGA (right) galaxies are shown as black symbols with 1σ errorbars.