Angular Unit Converter

Convert between degrees, radians, milliradians, microradians, arc-minutes, and arc-seconds. Calculate beam spread at a distance.

Angle Input
mrad
Beam Divergence Utility
Angular Conversions
Degrees (°)
0.06875°
Radians
0.00120rad
Milliradians
1.2000mrad
Microradians
1200.0µrad
Arc-minutes (′)
4.1253′
Arc-seconds (″)
247.5″
Beam Spread at 10 m
Radius growth (from full-angle divergence)
r = d × tan(θ_half)
6.0000mm
Diameter growth
Full beam spread = 2 × radius growth
12.000mm
Add your initial beam diameter to the diameter growth to get total beam size at the target distance. For Gaussian beams, this is approximate — the exact calculation requires beam waist and Rayleigh range.
Abridged Optics — Angular Unit Converter v1.01 rad = 206,265 arc-seconds. For beam displacement, solid angle, and error propagation calculations, see the Optical Geometry Calculator.

All information, equations, and calculations have been compiled and verified to the best of our ability. For mission-critical applications, we recommend independent verification of all values. If you find an error, please let us know.