The performance of functionals and basis sets is evaluated using density functional theory with polarized continuum model to calculate redox potentials of small organic compounds in acetonitrile. Pople basis sets 6-31G, 6-31G*, 6-31G**, 6-31+G*, 6-31+G**, 6-31++G** and functionals at different levels of the Jacob’s Ladder are studied: PW91, PBE, M06-L, B3LYP, PBE0, M06-2X, CAM-B3LYP, $\omega$B97X-D3. It is shown that performance studies should not be done considering oxidation and reduction reactions together, but analyzing them separately. Functional M06-2X has a more consistent and uniform response both in reductions and oxidations and the presence of diffuse functions in the basis sets is relevant to the accuracy of the predictions. The computational effort against accuracy is also evaluated.