HR diagram position of T Tauri stars with magnetic field measurements from near-IR spectroscopy from this work (filled circles) and from the literature (open circles). The radius of the circles is proportional to the square of the magnetic field strength. Filled light orange and filled dark orange circles represent ⟨ B ⟩_1.5 and ⟨ B ⟩₃ measurements, respectively, from Table 4. We overplot the zero age main sequence (ZAMS; dashed purple line), the evolutionary tracks for 0.5, 1, 2, and 3 M_⊙ (dark lines), and the limit between fully convective and partially convective interiors (dotted green line) from the Yale–Potsdam Stellar Isochrones grid (Spada et al. 2017). The key in the lower left corner gives the corresponding symbol sizes for magnetic field strengths of 1, 2, and 3 kG.