Due to their unusual structure and composition, BCC high entropy alloys (HEAs) are generally refractive and have favorable properties such as high service temperatures, strength, and ductility, making them desirable for high performance applications. In the present work, first-principles calculations using density functional theory were used to analyze stacking fault energies (SFE) in the AlNbTaTiV BCC HEA system. Special quasi-random structures and the GGA-PBE exchange correlation functional were used. “Twinning-sense” and “non-twinning-sense” stacking faults on the (112) plane, with ABCDEFA stacking, were investigated. Additionally, a method for predicting the error bars on calculations from the approximations to a random solution was introduced and analyzed. This work demonstrates a method of averaging and approximation that could improve the high throughput efficiency of database generation of HEA properties. Finally, the effect of BCC SFE values on deformation properties such as nano-twin nucleation and growth is discussed.