It is well known that current having non-negligible value could appear in metal sheet of single-core power cables. This current causes additional heating of the cable and consequently, decreases the cable current capacity. Total current flowing through the metal sheet of the single-core cables consists of circulation, eddy and capacitive components. Circulation current depends on cable geometry, material of metal sheet, arrangements of cables and cross-bonding method. Circulation current of three single-core cables laid in a flat formation is analysed in this paper for six different cases, and a general matrix equation for circulating current calculation is proposed.