We present numerical investigations on generating droplets in both single and double T-junction microfluidic devices using the Volume of Fluid (VOF) method. We validate our 2D simulation results with an experimental data reported in the past. The average pressure in the channel increases by 6% and capillary number by 16% for an increase in the width of side-channel from 50 μm to 100 μm in a single T-junction device. Similar increase in average pressure and capillary number is seen, for the increase in the width of one of the side channel in double T-junction device. The temporal variation of pressure in both the side channels shows that the pressure is lesser in the wider side channel. The average pressure in the channel decreases by 75% and capillary number by 15% for an increase in width of the main channel from 50 μm to 100 μm in a single T-junction device. Similar decrease in average pressure and capillary number is seen for the increase in the width of the main channel in double T-junction device. A gradual increase in the width of the main channel shows that, droplets generated in alternate regime when the width of the main channel is 1.4 times the width of side channel. In this regime, the temporal variation in pressure show a periodic change in both the side channel. Finally, in double T-junction device, the addition of surfactant has no significant effect on droplet generation in merging regime but it is seen in alternate regime.