In the title molecule, C16H14N2O, the dihydroquinoxaline moiety is not planar as there is a dihedral angle of 4.51 (5)° between the constituent rings. In the crystal, C—H...O hydrogen bonds form helical chains about the crystallographic 21 screw axis in the b-axis direction. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (51.7%), H...C/C...H (26%) and H...O/O...H (8.5%) interactions. The optimized structure calculated using density functional theory (DFT) at the B3LYP/6–311 G(d,p) level is compared with the experimentally determined structure in the solid state. The calculated HOMO–LUMO energy gap is 3.8918 eV.