The radius of the Earth is approximately 6,371 kilometers (km) or about 3,959 miles (mi).
To understand this better, the radius is the distance from the center of the Earth to its surface. It varies slightly depending on where you measure it due to the Earth’s oblate shape, which means it is slightly flattened at the poles and bulging at the equator. However, the average radius is what is commonly used in calculations and scientific references.
When measuring in kilometers, the figure 6,371 km is widely accepted. In miles, this translates to roughly 3,959 mi. Knowing the Earth’s radius is fundamental in various scientific fields such as geology, geography, and astronomy, as it helps in the understanding of the planet’s dimensions and its gravitational field.