Unit Descriptions
1 Arcsecond:1 Arcsecond is equal to exactly one thirtysix-hundredth arc degrees (1°/3600). In terms of radians (SI unit) this is π/648000 rad or approximately 4.848 137 x 10-6 rad.
1 Gradian:1 gradian is exactly 1/400 of a revolution or 2π/400 or 0.9°. In terms of the SI unit radians 1 grad is approximately 15.707 963 x 10-3 rad.