In this work, the dimensioning of a thermoelectric generator is carried out, applying the calculation scheme of reduced variables, which are the reduced current density (U), the reduced efficiency (η). The key quantity to calculate the parameters geometric, cross-sectional area A and length l of the legs, is the product uk; where u is the relative current density and k the thermal conductivity. Subsequently, the average thermoelectric properties were calculated, that is: coefficient average Seebeck (α¯), average thermal conductivity (κ¯) and average electrical resistivity (ρ¯), because in reality these properties depend on temperature, because in reality these properties depend on temperature. Average quantities and dimensional parameters were used to calculate and analyze generator power. The influence of the ceramic plate and metal bridge is also included in this analysis, taking into account their thickness (lceramic, lmetal), electri