I am not that great at Astronomy, but I asked this question to one of my scientist friend’s recently and here is what he had to answer.
Both Sun and the Earth are sort of almost perfect spheres. The Sun’s equatorial diameter is 1,391,400 Km and the Eearth’s equatorial diameter is 12,756 km. If you do the calculations the Sun is about 109 times bigger than Earth. If by size you mean volume, then the sun occupies about 10^3, or over 1,295,000 times the volume of the Earth. In case you want to go step further and compared them by mass, then the Sun has a mass of about 1.99*10^30 kg, and the Earth’s mass is 5.98*10^24 kg, thus the Sun is about 332,776 times as huge as the Earth. This is different from the ratio of their volumes because the Earth has a larger average density than the Sun.
By the way, the diameter of the Sun is 1,400,00 km and that is about 100 times the diameter of the Earth.