This paper presents the proposal of a load balancing algorithm implemented in two of the most popular controllers for Software Defined Networks (SDN): OpenDaylight and Floodlight. A comparative study in terms of the available bandwidth and delay time of the packet forwarding was performed by means of simulation modeling in a base network in which a shortest path algorithm was implemented as well. The results show that the proposed load balancing algorithm improves significantly the performance of a SDN in terms of the offered QoS of a OpenDaylight based controller. The effect of the proposed load balancing algorithm in the Floodlight controller shows a smaller impact mainly on the bandwidth allocation due to its in-build modules that by default perform specific routing and forwarding operations efficiently according to the traffic demand.