This paper presents a new algorithm for short-circuit currents calculation in distribution networks in which distributed generators are connected. The specifications of the IEC 60909 Standard are applied, in which the fault is replaced by an equivalent voltage source. The algorithm consists in two steps: a forward sweep, in which the aggregated impedances between each bus and the neutral point are calculated, and the backward sweep, in which the short-circuit currents flowing in the network branches are determined. The IEEE 33 bus test network is used for numerical calculations, considering 5 distributed generators.