We present simple and complete empirical relations to predict the angle of beam divergence in terms of normalized frequency and aspect ratio of a single-mode trapezoidal index fiber. This is done for the far-field characterization over a long range of normalized frequencies without the calculation of normalized spot sizes. On comparison, we observe an excellent match of our results with exact values establishing the validity of our formulation. The formulation should attract attention as a simple alternative to the rigorous methods of estimating the angle of beam divergence for such fibers. It can be widely used by system users and developers for much better control over far-field related calculations and experiments. © 2017 Society of Photo-Optical Instrumentation Engineers (SPIE).