Ok, I took it backwards! For CSGO it isn't a problem, just adjust the sensitivity accordingly. But for Windows you have a little problem, I don't think you can make 450 feel like 400 in a sensible manner.
Are you used to 450 both in Windows and in CSGO? And is 900 DPI an option?
If so, set the mouse to 900 DPI, Windows Pointer Speed to 4 and CSGO to 1.1 (and keep raw input on). This will keep everything virtually identical.
This is by design since turning raw input off generally result in less accuracy. But I'll actually update it now to support raw input both on an off as a special option.
360 distance conversion should only be used for hipfire sensitivity.
For ADS/Scopes you should use Viewspeed or Monitor Distance, regardless of whether you are converting from ADS/scope or hipfire.
Viewspeed and Monitor Distance can be used for hipfire as well, depending on your preference.
The output in the calculator will calculate this for you based on your resolution. Look for the "Actual HFOV" value.
This image should explain things a bit. For aspect ratio wider than 4:3, extra FOV is added on while the 4:3 portion in the middle stays the same.
Just fixed the alpha calculator, was a few updates to the database not correctly implemented, so it may have behaved a bit weird. Should be sorted now!
Can you screenshot your inputs? Thanks!
Edit: The first thing that comes to mind is that you have the wrong location selection, i.e. Config File instead of In-game. If not, show me a screenshot and I'll take a look at it.
They are using different approaches to the calculations, so they are both correct in their own way. The one in the alpha calculator have a few issues with resolution though. I will solve them later and integrate it into the main calculator.
Calculator updates
All games that had multiple entries with different options, like Battlefield 1 with ADS FOV on or off and PUBG with in-game and config file sensitivity, are now merged into one.
The calculator now have three new fields:
Special Option 1 and 2 will have options for the game that affects sensitivity. This can be options like USA and ADS FOV for BF1, different game modes for Fortnite or different versions of the game like Metro 2033.
In the new Location field you can select if you want in-game or config file sensitivity (where they are supported). In some cases console and regedit are also options.
Updated games
A lot of games have had their sensitivity formulas updated. These updates are changes from numbers to constants or fractions. Examples of this are 31416 being changed to PI*10000 and 162.016 changed to 180000/1111.
The implication of this in terms of sensitivity is not even measurable, but in some cases you might get a slightly different sensitivity value if the game supports enough decimals.
The following games are updated:
ARK
Battlefield 1
Battlefield 3
Battlefield 4
Battlefield Hardline
Bioshock
Deceit
Just Survive
H1Z1
Miscreated
Morrowind
Oblivion
Planetside 2
Prey (2017)
Reflex
S.T.A.L.K.E.R. - Call of Pripyat
Space Hulk: Deathwing
Squad
Star Wars Battlefront 2
The Culling
The Elder Scrolls Online
theHunter: Call of the Wild
Tom Clancy's Rainbow Six Siege
Tom Clancy's The Division
Tower Unite
Unreal Tournament 4