We investigate the vibrational properties of zigzag and armchair single-layer graphene sheets (SLGSs) using the molecular mechanics (MM) approach. The natural frequencies of vibration and their associated intrinsic vibration modes are obtained. Vibrational analysis is performed with different chirality and boundary conditions. The simulations are carried out for three types of zigzag and armchair SLGS. The universal force field potential is used for the MM approach. The first four natural frequencies are obtained for increasing lengths. The results indicate that the natural frequencies decrease as the length increases. The results follow similar trends with results of previous studies for SLGS using a continuum structural mechanics approach. These results have shown the applicability of SLGSs as electromechanical resonators.