How much wider is the Earth at the equator compared to the poles?

The Earth is not a perfect sphere; it’s actually an oblate spheroid, meaning it is slightly flattened at the poles and bulging at the equator. This shape results in the equatorial diameter being larger than the polar diameter.

To understand the difference in width, we look at specific measurements: the equatorial diameter of the Earth is about 7,926 miles, whereas the polar diameter is approximately 7,900 miles. This results in a difference of about 26 miles, which is often rounded to 27 miles in many contexts.

This difference is significant in fields such as GIS, where accurate representations of the Earth’s surface are crucial for mapping and analyzing spatial data, demonstrating how geodetic measurements must take the Earth's shape into account.