Result = value × (factor of the unit you convert from) ÷ (factor of the unit you convert to), every factor being the size of the unit in degree: 1 radian = 57.2958 degree 1 gradian = 0.9 degree 1 arcmin = 0.01667 degree 1 arcsec = 2.77778 × 10-4 degree 1 revolution = 360 degree
Leaving a scientific calculator in DEG mode for an angle in radians, or the reverse. sin 30 is 0.5 only when the 30 is in degrees; sin of 30 radians is −0.988.
Reading a gradian as a degree. A full turn is 400 gradians, so 1 gradian = 0.9°.
Counting arcminutes and arcseconds in hundreds. They go by 60: 1° = 60 arcmin = 3600 arcsec, so 0.5° is 30 arcmin, not 50.
One of the unit converters in the Chemistry Calculator Suite,
alongside its chemistry, physics and maths tools. Nothing is behind a login and no value
you type is sent anywhere — the conversion runs in your own browser.
The Angle converter above is the live tool — it converts right here on the page. The link under it opens the full suite with this set already selected.