The actual diameter of a jet at the breakup point is a function of the jet length. In those cases where the jet is either expanding or contracting, it is essential to know the jet length and diameter at breakup in order to predict drop diameter accurately. Drop diameters with single and multiple nodes were predicted by applying Tomotika's stability analysis and a model of jet diameter at breakup. The effects of small nozzle diameter, nozzle velocity, and viscosity of continuous phase on drop diameter are reported Experimental drop diameters were compared with the predicted diameters; agreement was very good.