Solid angle unit conversion table

This table contains conversions between almost all solid angle units. Some units of solid angle are common and some are relatively rare. This is a good query tool.

Name of unitSymbolDefinitionRelation to SI units
spat≡ 4π sr– The solid angle subtended by a sphereat its centre.7001125663699999999♠12.566 37 sr
square degreedeg 2; sq.deg.; (°) 2≡ (​ π180) 2sr6996304620000000000♠0.304 62×10 −3sr
steradian(SI unit)srThe solid angle subtended at the center of a sphere of radius r

by a portion of the surface of the sphere having an area r2.
A sphere subtends 4π sr.

= 1 sr