Angle conversion starts with the radian
The radian is the SI coherent unit of plane angle. CalcOS stores degree-family relationships symbolically with π and converts to a numerical value only at the calculation boundary.
degrees × π ÷ 180 = radians
This preserves the exact governing definition instead of presenting a rounded decimal approximation as an exact factor.
Supported plane-angle definitions
| Unit | Exact relationship | Common context |
|---|---|---|
| degree | π/180 rad | navigation and everyday geometry |
| arcminute | π/10,800 rad | astronomy and coordinates |
| arcsecond | π/648,000 rad | high-precision angular measure |
| gradian | π/200 rad | surveying and some calculators |
| turn | 2π rad | rotation and phase |
Arcminutes are not time minutes
The prime and double-prime symbols denote subdivisions of a degree: 60 arcminutes equal one degree, and 60 arcseconds equal one arcminute. They are angle units, not durations.
Popular angle converters
Authoritative reference: BIPM SI Brochure, Table 8.