A self-consistent model of single-stage electrohydrodynamic thrusters is proposed in order to compare and study their performances in terms of net thrust production and thrust-to-power efficiency. Simulations of three thruster's cathode configurations (conical, cylindrical, and funnel-like) at a working pressure of ≃ 66.7 Pa (0.5 Torr) were conducted. Three working gases were employed: argon (Ar, Ar*, and Ar+), nitrogen (N, N+, N 2 , N2 + , and N4 + ), and oxygen (O, O+, O - , O 2 , O2 + , and O2 - ). We found the funnel-like cathode configuration to produce the highest amount of thrust comparing with the other studied cathode geometries. Additionally, nitrogen gas presented the highest net thrust of 5.2 nN with a thrust-to-power ratio of 0.94 μN/W. Although the thrust obtained for oxygen is more than one order of magnitude lower than nitrogen's, the thrust-to-power ratio obtained is more than three times greater.