Input energy has long been recognized as a better demand parameter for expressing the effects of ground motions on structures as compared to accelerations (forces) or displacements (deformations) induced by ground motions. Previous research has clearly revealed the weak dependence of spectral input energy on viscous damping ratio and inelastic response, which is a clear advantage for expressing the demand of ground motions on structural systems in performing analysis and design. Moreover, the duration of the earthquake excitation, hence the magnitude of the causative earthquake is well represented by the input energy spectrum, which is a function of the initial structural period and ground motion intensity only. The main missing point in energy-based approaches however is the energy dissipation capacity of structural components. A method is proposed in this study for estimating the energy dissipation capacity of structural components, particularly the plastic hinges of flexural members in structural frames. The energy dissipation capacity of a plastic hinge is expressed in terms of a capacity curve, which gives the number of equivalent full cycles at the maximum deformation (i.e. the maximum rotation or curvature) at which the cyclic energy dissipation capacity falls below a limiting performance target. The proposed procedure is tested on a full-scale reinforced concrete column, tested under both constant amplitude and variable amplitude loading protocols.