Upper panel: mean magnetic field strength as a function of stellar angular velocity for 1, 0.8, and 0.5 M_⊙ stars (solid, dotted, and dashed lines, respectively). The insert shows the mean magnetic field as a function of the Rossby number. The Sun’s range of B_∗f_∗ = 2 − 7.7 G is shown as a vertical bar. Middle panel: mass-loss rate as a function of stellar angular velocity for 1, 0.8, and 0.5 M_⊙ stars (solid, dotted, and dashed lines, respectively). The Sun’s present day mass-loss is shown as an open circle. Lower panel: angular momentum loss rate normalised to the Sun’s as a function of angular velocity for 1, 0.8, and 0.5 M_⊙ stars (solid, dotted, and dashed lines, respectively). We used , and Ω_⊙ = 2.87 × 10^-6 s^-1 (Weber & Davis 1967).