We employed the APSYS software to perform 3D electrical and ray-tracing simulations on micro-ring light-emitting diodes (LEDs) to verify previous experimental findings that they have higher extraction efficiency than micro-disk and broad area LEDs. 3D ray-tracing indicates the importance of inter-ring optical interactions. Furthermore we found that the higher light extraction efficiency is at the expense of reduced internal quantum efficiency (IQE) as injection current is increased.