Top left: the comparison to previous works. The dots show the convection zone mass at 4.61 Gyr. The data from J. Sevilla et al. (2022) are derived from their MESA input files uploaded to Zenodo. (Their work mainly focused on the abundance change and did not consider solar calibration.) The gray lines are from M. H. Pinsonneault et al. (2001), corresponding to different ages and metallicities. Top right: the mass fraction of the convection zone under different effective temperatures and surface gravities. The red dots highlight stars of solar metallicity (Z = 0.0142) and age 4.61 Gyr, whereas the other points are sampled from the whole parameter space. Middle Left: the mass fraction of the convection zone under different masses and metallicities. Middle Right: the mass fraction of the convection zone under different masses and ages. Bottom: the evolution track of the stars with different masses and metallicity. Red dots represent data for 79 solar twins from M. Bedell et al. (2018), with the hollow ones falling outside the grid parameter space and thus failing to compute convective-zone masses.