The multilevel inverters are predominantly applied for medium/high-voltage high-power industrial applications. The stacked multicell (SM) converter is one of the promising derived-topologies from flying-capacitor-multicell (FCM) converter which has an increased performance. Discerning that conduction power loss exploration is a beneficial procedure in design phase of the multilevel inverter, this study suggests an analytical method for computation of the conduction power losses in SM converters. To achieve this, formulas are derived on the basis of SM converter modulation index, power factor, and load peak current for computation of rms and average currents flowing through power switches like as IGBT and freewheeling diode. The numerical results of the derived equations for computation of the rms and average currents flowing through IGBTs and freewheeling diodes are compared with simulation results. Numerical computations matched simulation results which validates the derived formulas. Then, proposed closed-form solutions for analytical computation of the rms and average currents are utilized to calculate the conduction power losses in a 12.4-MVA 3.3-kV 9-level (line-to-line) SM converter at a specific junction temperature. For this purpose, a 2.5-kV 1.5-kA IGBT module from ABB is considered as a power switch.