The equations of energy, continuity, and momentum are solved to give axial and radial values of temperature, pressure, and axial and radial velocity for vertical arcs stabilized by natural convection. It is assumed that the electric field is purely axial and magnetic forces are neglected. For a free‐burning arc of 10 A in air, calculated temperature and velocity profiles are in good agreement with published experimental results. For an arc in an enclosed vertical tube of mercury vapor, results of central velocities as a function of axial position for a 2.9‐A arc are in good agreement with the experimental results of Kenty. Comparisons are made of the differing properties predicted for free‐burning arcs of 10 A in air, sulfur hexafluoride, and hydrogen. Removal of the maxima in the thermal conductivity has a negligible effect on the degree of predicted arc constriction in SF6. Convective flow in all calculations is assumed to be laminar. The influence of radial pressure variations is found to be almost negligible.