Multiple power system equipment damage from strong geomagnetic disturbance (GMD) can significantly disrupt power grid operation. This has happened twice: in 1989, in North America and the United Kingdom and, in 2003, in Scandinavia and South Africa. Modern bulk high-voltage power grids were designed more than 60 years ago for achieving more economic benefits in power transfer. In turn, high-voltage, and especially the lately designed ultrahigh-voltage, grids are more vulnerable to GMD. It is anticipated that the demand of detailed study of power grid’s vulnerability to GMD will expand with broader awareness of the negative effects. The common approach requires the knowledge of the data on geophysical parameters of the study region, which is not accessible to the specialists without relevant background. In this paper, an alternative algorithm for preliminary evaluation of power grid’s robustness to GMD is proposed. It takes into account various critical factors and provides a useful tool for stakeholders to identify potentially weak power grids and develop mitigation procedures beforehand. The advantage is that this algorithm can be used by specialists who do not have a comprehensive understanding of the GMD effect on power grid operation.