That's the same 360 distance. You can't do that for scopes, you need to convert it using a conversion method based on the FOV.
The conversion you have linked does what you are asking, where you want the Fortnite ADS to match the 37.89 (widow) and 51.47 (ashe) sensitivity. The Targeting (ADS) sensitivity in Fortnite is almost the same FOV as Ashe, so it also have about the same 360 distance.