Square degree

Square degree
Square degree
Unit of	Solid angle
Symbol	deg2
Conversions
1 deg2 in ...	... is equal to ...
SI units	≈ 3.04617×10−4 sr

A square degree (deg²) is a non-SI unit measure of solid angle. Other denotations include sq. deg. and (°)². Just as degrees are used to measure parts of a circle, square degrees are used to measure parts of a sphere. Analogous to one degree being equal to ⁠ $π$ /180⁠ radians, a square degree is equal to (⁠ $π$ /180⁠)² steradians (sr), or about ⁠1/3283⁠ sr or about 3.046×10⁻⁴ sr.

The whole sphere has a solid angle of 4 $π$ sr which is approximately 41253 deg²:

4\pi \left({\frac {180}{\pi }}\right)^{2}\,{\deg }^{2}={\frac {360^{2}}{\pi }}\,\,{\deg }^{2}={\frac {129\,600}{\pi }}\,\,{\deg }^{2}\approx 41\,252.96\,\,{\deg }^{2}