The interaction of low-energy electron collisions with molecules may lead to temporary anions via resonant processes. While experimental measurements, e.g. electron transmission spectroscopy or dissociation electron attachment spectroscopy, are efficient to characterize the temporary anions, simulating the electron attachment is still very challenging. Here, we propose a methodology to calculate the resonance energies of the electron attachment using ab initio (TD)-DFT calculations together with two different basis sets: a large basis set with diffuse functions to compute the vertical electron affinity, and a smaller one to calculate the excitation energy of the anion. To demonstrate the capabilities and the reliability of this computational approach, 53 resonance energies from 18 molecules are calculated and compared to experimental data.