Earth's Radius

Earth's radius is the distance from its center to its surface. Imagine stretching a straight line from Earth's core directly outward to the surface; that length is approximately 6,371 kilometers (3,959 miles). The radius helps us understand Earth's size and shape, which is mostly spherical but slightly bulging at the equator due to rotation. This measurement is essential for calculations in geography, navigation, and science, providing a foundational reference for understanding Earth's dimensions and how it functions as a planet.