BiFeO3 (BFO) is the model and most promising multiferroic material as both ferroelectric and magnetic orders coexist at room temperature. In order to exploit his functionalities in modern devices, one needs to understand how these orders and especially its complex magnetic structure made of a G-type antiferromagnetic order superimposed with a cycloidal modulation (62 nm) are affected in thin film form. Up to know, most of the experimental works (including ours) have been done in the compressive strain where the cycloid has been shown to extend its period with misfit strain until disappearing at high strain. In contrast, reports on the tensile strain side are scarce despite the magnetic richness. Indeed, we theroetically showed that BFO under tensile strain exhibits another cycloidal modulation we want to address by determining its propagation vector and period in this proposal.