The mean radius of Uranus is 15,792 miles (25,362 kilometers), giving a diameter four times that of Earth

The rapid spin of Uranus causes a slight bulge around the center. It has a radius of 15,517 miles (24,973 km).

If you were to take a walk around the equator of Uranus — a trip that might be challenging since the planet has no solid surface — you would travel 99,018 miles (159,354 km).

How heavy is Uranus?

Uranus weighs in at 86 septillion kilograms (just under one trillion trillion trillion). The planet has a volume of 6.83×1013 cubic kilometers.

The density of Uranus is 1.27 grams per cubic centimeter, making it the second least dense planet in the solar system. Its low density indicates that it is predominantly composed of ice rather than gas.

Internal Structure

Uranus’ mass is roughly 14.5 times that of Earth, making it the least massive of the giant planets. Its diameter is slightly larger than Neptune‘s at roughly four times that of Earth. A resulting density of 1.27 g/cm3 makes the planet the second least dense after Saturn.

This value indicates that it is made primarily of various ices, such as water, ammonia, and methane.

The total mass of ice in its interior is not precisely known because different figures emerge depending on the model chosen; it must be between 9.3 and 13.5 Earth masses.


The icy composition of Uranus and Neptune both differ from the heavier gas giants, Jupiter and Saturn, and have caused them to be labeled “ice giants.”

The distance of the planet from the sun is significant, resulting in the coldest atmosphere in the solar system and accounting for the icy temperatures.

The composition of Uranus’ atmosphere is different from its bulk, consisting mainly of molecular hydrogen and helium. The helium molar fraction, i.e. the number of helium atoms per molecule of gas, is 0.15±0.03 in the upper troposphere, which corresponds to a mass fraction 0.26±0.05. 

This value is close to the protosolar helium mass fraction of 0.275±0.01, indicating that helium has not settled in its centre as it has in the gas giants.