In the first one you are getting 40 cm for hipfire, while all the others are converted using MDV 0% (so the tracking speed is the same for all the aims).
In the last one you are directly calculating what 40 cm is for the aim.
Hope that clears it up
The color will change from green (perfect match) through orange (about 2% off) to red (about 4% off) depending on the discrepancy.
The discrepancy is the difference between a perfect match and what you actually get due to limitations in rounding.
The only way to fix this is to either use config file sensitivity with more decimals supported, or to fine-tune your DPI if your driver supports it (or through a 3rd party program).
You can see the required DPI for a perfect match if you set the calculator mode to "Advanced".
Since Fortnite is 3rd person and has a quite narrow FOV, it's really hard to make it "feel" the same as a 1st person game with a wider FOV.
What you have tried is the correct way to go about it, but I would suggest also trying 133 and 178%.
I'm not sure when it happened, but sensitivity in this game has a lot of acceleration and smoothing now, so I have to remove it. There's no way of getting a stable sensitivity, it's all over the place.
Game added
The Outlast Trials
Games updated
Roblox - Added Tournament Grounds
Dirty Bomb - Added sniper scope.
Call of Duty: Modern Warfare II (2022) - Added all scopes.
The First Descendant - Added all aims.