The Jupiter radius or Jovian radius (R_J or R_Jup) has a value of 71,492 km (44,423 mi), or 11.2 Earth radii (R_Earth)^[2] (one Earth radius equals 0.08921 R_J). The Jupiter radius is a unit of length used in astronomy to describe the radii of gas giants and some extrasolar planets. It is also used in describing brown dwarfs.

Jupiter radius
The size of Jupiter compared to Earth
General information
Unit system	astronomy
Unit of	length
Symbol	RJ or RJup,R♃
Conversions
1 RJ in ...	... is equal to ...
SI base units	7.1492×107 m[1]
English units	44423 mi

In 2015, the International Astronomical Union defined the nominal equatorial Jovian radius to remain constant regardless of subsequent improvements in measurement precision of R_J. This constant is defined as exactly:

${\displaystyle {\mathcal {R}}_{\mathrm {eJ} }^{\mathrm {N} }}$ = 7.1492×10⁷ m

Similarly, the nominal polar Jovian radius is defined to be exactly:

${\displaystyle {\mathcal {R}}_{\mathrm {pJ} }^{\mathrm {N} }}$ = 6.6854×10⁷ m^[1]

These values correspond to the radius of Jupiter at 1 bar of pressure. The common usage is to refer to the equatorial radius, unless the polar radius is specifically needed.