How Big is the Sun?

The Sun represented as a basketball to show the scale of the Sun and the planets relative to each other. (credit: Courtesy of SOHO)

The Sun is really really big! It is difficult to get a true feel for how big it is because nothing in our daily life comes even close. But we can use objects that we are familiar with to provide us with a scale that can allow us to at least see how big the Sun is compared to the Earth and the other planets in our solar system.  If you think of the Sun as a basketball, the Earth would only be the size of the head of a pin.

  • If the Sun were a hallow ball, it would take about one million Earths to fill it.
  • The Sun is 110 times wider than the Earth. So 110 Earths would fit across the diameter of the Sun.
  • The mass of the Sun (the amount of stuff) is 330,000 times that of the Earth.
  • The mass of the Sun accounts for 99.86% of the total mass (total amount of stuff) in the solar system.

The Sun observed by SDO on April 6, 2011 in 304 Angstrom light.

Zooming in on the 304 Angstrom image of the Sun to show the relative size of the Earth compared to the Sun and to a solar prominence on the Sun's limb.


  1. It would be interesting if the comparison of the earth to a pinhead would also include relative distance. How far would that pinhead be from the basketball? I once read that if the sun were a basketball then Jupiter would be the size of a mosquito a mile away. I’m wondering if that is accurate.

  2. How far away would the 2mm pinhead (earth) be from the basketball (sun)? I read somewhere 30 meters, but would like to see that calculated. I suck at math.

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  4. How far from the Sun would the Earth be if the Sun were the size of a basketball?

    According to Wikipedia ( a standard basketball is about 75 cm (7.2×10^-4 km) in diameter and according to this website the sun is 1.4×10^6 km in diameter. Another page on this website ( states the Sun is 1.50×10^8 km away from the Earth.

    We want to make these ratios equal:
    Basketball diameter / Sun diameter = Distance to basketball / Distance to Sun
    So we substitute our values:
    7.2×10^-4 km / 1.4×10^6 km = ? / 1.50×10^8 km
    Then multiply both sides by 1.50×10^8 to isolate ?:
    Distance to basketball = 1.50×10^8 * 7.2×10^-4 / 1.4×10^6 = 10×10^4/ 1.4×10^6 = 7.1×10^-2

    We find the Earth would be 0.071 km (0.044 miles, roughly 230 feet) away from the Sun if the Sun were the size of a basketball.

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