Muons in extensive air showers (EAS) are a sensitive probe for the primary cosmic ray mass and the physics of hadronic interactions at very high energies, hence it is important to precisely measure and carefully analyze this particular shower component. In practice, however, such measurements are difficult to carry out due to the penetrating nature of muons and their low density in the shower. This way just in a few experimental facilities the shower muon component has been measured event-by-event in combination with other EAS observables. One of them was the multicomponent air shower experiment KASCADE-Grande, which was designed to study cosmic rays in the energy interval from $1$ PeV to $1$ EeV and was located at the site of the Karlsruhe Institute of Technology, Germany at $110$ m a.s.l. In this work, we will present an analysis of the KASCADE-Grande data in terms of the muon content ($E_\mu > 230$ MeV) of cosmic-ray induced air showers as a function of the primary energy (E = $10$ PeV $- 1$ EeV) and the zenith angle ($< 35^\circ$). We test also the predictions on the shower muon content of the post-LHC hadronic interaction models EPOS-LHC, QGSJET-II-04, SIBYLL 2.3 and SIBYLL 2.3c by comparing the model expectations with experimental results.