Earth is the fifth largest planet in our solar system and the largest of the terrestrial planets. Its equatorial diameter is about 7,926 miles (12,756 kilometers), while the diameter measured from pole to pole is slightly smaller, approximately 7,900 miles (12,712 kilometers), due to its equatorial bulge caused by rotation

. The radius of Earth at the equator is about 3,963 miles (6,378 kilometers), and at the poles, it is about 3,950 miles (6,356 kilometers)

. This shape makes Earth an oblate spheroid rather than a perfect sphere. Earth's circumference at the equator is roughly 24,901 miles (40,075 kilometers), and the polar circumference is slightly less, about 24,860 miles (40,008 kilometers)

. In terms of surface area, Earth covers about 197 million square miles (510 million square kilometers), with about 29% being land and 71% covered by water

. Its volume is approximately 260 billion cubic miles (1.086 trillion cubic kilometers), and its mass is about 6 x 10^21 metric tons

. The average density of Earth is around 5.5 grams per cubic centimeter, making it the densest planet in the solar system

. In summary:

• Equatorial diameter: ~7,926 miles (12,756 km)
• Polar diameter: ~7,900 miles (12,712 km)
• Equatorial radius: ~3,963 miles (6,378 km)
• Polar radius: ~3,950 miles (6,356 km)
• Equatorial circumference: ~24,901 miles (40,075 km)
• Surface area: ~197 million square miles (510 million km²)
• Volume: ~260 billion cubic miles (1.086 trillion km³)
• Mass: ~6 x 10^21 metric tons
• Density: ~5.5 g/cm³