The purpose of this master's thesis is to simulate the surge wave distribution on a real power transformer winding during a lightning impulse test. The general purpose and procedure of a standardised lightning impulse test is presented. The winding of a power transformer is represented as a lumped parameter model, where the electric characteristics of the winding are incorporated as resistance, parallel and series capacitance and self and mutual inductance. Different simple analytical and more complex numerical methods for parameter calculation are presented. The numerical methods make use of the finite element method with FEMM 4.2. The lightning impulse test on the model is simulated using numerical circuit analysis in LTspice. The model is further expanded to enable the calculation of voltage transfer from the tested winding to the neighbouring winding. The methods used to calculate the additional parameters are the same. The results of the surge distribution and transfer simulation are evaluated in comparison to actual measurements of a lightning impulse test on the analysed power transformer.