How big is Venus?

Venus, the second planet from the Sun, is quite similar to Earth in terms of size, mass, and density. In fact, Venus has been called Earth’s twin. Venus’s mean radius is 6,051.8 kilometers (3,760.4 miles), which is about 95 percent of Earth’s radius at the Equator. This makes Venus nearly as large as our home planet, giving it a comparable surface area and volume.

The mass of Venus is 4.87 x 10²⁴ kilograms, which is 81.5 percent of Earth’s mass. This similarity in size and mass results in a similar density: 5.24 grams per cubic centimeter for Venus, compared with Earth’s 5.52 grams per cubic centimeter.

Venus’s surface gravity is also quite similar to Earth’s. Humans standing on Venus would possess about 90 percent of their weight on Earth. Venus has a relatively slow rotation, taking about 243 Earth days to complete one rotation in respect to the stars. Because of its slow rotation, it maintains a highly spherical shape, unlike planets with faster spins that exhibit a bulging equator and a slight flattening at the poles.