Disk truncation radius R_t in units of stellar radius R_⋆ versus accretion rate Ṁ_⋆ for a 2 Myr old 0.7-M_⊙ star with B_⋆ = 0.5 kG and P_⋆ = 2 days. The solid line shows the expression given in Eq. (1). The dashed line shows the first term of Eq. (1). The horizontal dashed line marks the co-rotation radius. In the region of Ṁ_⋆ ∼ 10⁻⁷ M_⊙ yr⁻¹, the condition R_t ≥ R_⋆ would be violated for the given parameters, so these values have been excluded.