KASCADE-Grande is a multi-detector experiment at Forschungszentrum Karlsruhe, Germany for measuring extensive air showers in the primary energy range of 100 TeV to 1 EeV. This contribution attempts to provide a synopsis of the current results of the experiment. In particular, the reconstruction of the all-particle energy spectrum in the range of 10 PeV to 1 EeV based on four different methods with partly different sources of systematic uncertainties is presented. Since the calibration of the observables in terms of the primary energy and mass depends on Monte Carlo simulations, we compare the results of various methods applied to the same sample of measured data. In addition, first investigations on the elemental composition of the cosmic particles as well as on tests of hadronic interaction models underlying the analyses are discussed.