Stellar mass (left panel), and radius (right panel) as a function of the effective temperature. Stars are plotted using different colours and symbols according to their metallicity. Several fits for fixed metallicity values are plotted: +0.15 (dashed line), +0.00 (solid line), −0.15 (dashed-dotted line), and −0.30 (dotted line). Upper left panel: differences between the mass obtained from Eq. (5) and those derived by using the relationship reported by Henry & McCarthy (1993). Upper right panel: differences between the radius derived from Eq. (6) and by using Eq. (4).