Several notions of topological entropy for non necesarily continuous semiflows were introduced because the classical notion of topological entropy does not work cause the discontinuity of these systems. In particular, in Jaque and San Martin (J Differ Equ 266:3580–3600, 2019) was studied the definition of topological entropy by using separated and spanned sets, respectively, associated to a certain pseudosemimetric. Besides, it was proved that for regular impulsive semiflows the notion obtained by using separated sets can be computed trough a suitable conjugacy with a continuous system. In this paper, we will show that the same result holds for the entropy defined by spanning sets by adding a mild condition on the semiflow. This result extends, for this kind of semiflows, those obtained by Bowen (Trans Am Math Soc 153:401–414, 1971) and Dinaburg (Dokl Akad Nauk SSSR 190:19–22, 1970) respectively for the continuous case.