Abstract: Published literature suggests that the reaction zone length is related to the charge diameter in an explosives detonation. The research presented in this study made an effort to establish a possible interrelationship between reaction zone thickness and explosive column length as opposed to charge diameter. For the purpose of experimental validation, explosive charges of different length were prepared keeping the density and diameter unchanged. All charges were fired against aluminium witness blocks and the dimensional elements of the indentations were measured. The results obtained from the study had shown that the reaction zone thickness was related to charge length. An equation was proposed for the detonation velocity prediction relating to explosive height.