This paper describes the short circuit calculation method in matrix form. In the first part of the paper, the types of short circuits were theoretically explained and expressions were obtained for short circuit currents and voltages after the failure, assuming that the voltage before the failure was 1 p.u. When calculating, it is important to know the impedance values of the circuit elements due to the formation of the node impedance matrix. We have broken down the currents and voltages into their symmetrical components and thus made the calculation easier. In the second part of the work, for the analysis of short-circuit currents, we used Matlab in which we entered data, formed the node impedance matrix and calculated short-circuit currents using theoretically obtained expressions. Finally, on the example of the electrical network, a comparison was made of the obtained results for currents through the branches and voltages on the busbars, obtained with the help of Matlab, with the results obtained with the help of Powercad. From the attached tables, we can see that there are no excessive deviations in the results.