Iron toxicity is a key factor for tissue damage in iron-overloaded patients, with induced heart failure being the main cause of death. T2∗-weighted magnetic resonance imaging (MRI) has been established as the method of choice for evaluating iron content with strong correlation with biopsy, where T2∗ < 20 ms and T2∗ < 10 ms at 1.5T indicate iron overload and severe iron overload, respectively. Recently introduced dual-energy computed tomography (DECT) has the potential for evaluating iron overload without energy-dependent CT attenuation or tissue fat effects. This study investigates the performance of DECT for iron mapping in scans of calibrated iron phantoms, and compare the results to MRI T2∗ imaging. The results show that DECT has high accuracy for evaluating iron overload, comparable to that of MRI T2∗ imaging, which might help in patient staging based on the severity of iron overload, independent of the implemented imaging energy.