The equivalent circuit method of Stening (1968) is used to calculate current distributions in the vicinity of the equatorial electrojet. Both height and latitude profiles are obtained which show reasonable agreement with observations. The tube of magnetic force model employed in the calculations is useful in understanding some of the variations in the electrojet. Changes in height of the electron density profile are shown to lead to changes in the maximum current density of the electrojet. Two further problems are discussed: (1) the double peak structure in the current density height profile and (2) the relationship between the instabilities observed by VHF backscatter and ground-based magnetic measurements.