All of what you read below applies to Battlefield 6, as tested in Labs and the Open Beta, including my own personal settings, summarized at the bottom of this sheet.
This is the new version of my old guide for BF4 through BF2042, for Battlefield 6. BF6 uses a revised mouse input system with a lower base sensitivity and a higher max sensitivity, and by quite a lot too. Editable both in-game with decimal points via arrow keys, and in config files, with input that isn't just emulated controller input like 2042, it's a paradise by comparison.
If you wish to more finely tune your sensitivity, keep reading.
Navigate to:
BF6 Open Beta:
Documents\Battlefield 6 Open Beta\settings\PROFSAVE_profile
BF6:
Documents\Battlefield 6\settings\PROFSAVE_profile
and open the file in a text editor of your choosing.
Next:
Ctrl+F search for GstInput.MouseSensitivity
And the fun bits:
Each time you increase the sensitivity in game by 1, the long decimal number next to GstInput.MouseSensitivity increases by 0.000750 with a minimum of 0.000000 and a maximum of 0.075000, which correspond to 0 and 100 in the game menu, respectively. If you set the game menu to 5, the decimal will show 0.003750. Simply multiply the game menu value by 0.000750 with a calculator to find the decimal value you wish to start with.
To dial in the sensitivity in finer points, the game menu allows adjustment in 0.1 ticks or tenths of a tick, or 0.000075 in the settings file. This is done by selecting the sensitivity slider and then using left and right arrow keys. This should be perfecly fine for the vast majority of players, even 80%-95% of Snipers, as adjusting less than one tenth of a tick is barely able to be felt by all but the most finely aware players. To adjust even more finely than this, I would suggest shifting by 0.000010 at the least, anything less is peanuts and you won't notice much. If that is too little, adjust by 0.000037, or twentieths (1/20) of a tick.
All of the above also goes for the vehicle sensitivity, which can be found the next line down in the file as GstInput.MouseSensitivityVehicle.
This is 100% optional, but it is nice. In essence, based on your aspect ratio, this will even out sensitivity across optic zoom in game. Older games like CS:GO have something of similar or identical operation, but locked to the coefficient for 4:3 displays, as that is what most players are used to for this system. Battlefield is one of the few games that allows you to alter this.
If using a 16:9 display, set the coefficient to 177.7% in game Settings -> Mouse & Keyboard -> Infantry -> Control Settings, but if you want it finer, go to:
BF6 Open Beta:
Documents\Battlefield 6 Open Beta\settings\PROFSAVE_profile
BF6:
Documents\Battlefield 6\settings\PROFSAVE_profile
and find GstInput.UniformSoldierAiming and set its value to 1, then find GstInput.UniformSoldierAimingCoefficient and set that value to 1.777777.
For 4:3, set the coefficent to 133.3 in game, or 1.333333.
For 21:9 Ultrawide, set the coefficient to 233.3 in game or 2.333333.
For 32:9 Ultrawide, set the coefficient to 355.5 in game or 3.555555.
If you want to have higher sens in hipfire and much lower sens when ADS, set your coefficient to 0 in game or 0.000000 in the settings file.
Same as above, though the menu is found at Settings -> Mouse & Keyboard -> Vehicles -> Control Settings, and the lines to find in the config file are GstInput.UniformVehicleAiming, to enable and disable it, and GstInput.UniformVehicleAimingCoefficient to set the coefficient. Set that the same as you have your Infantry aim for consistency, or pick your poison.
Every time you adjust the sensitivity in the PROFSAVE_profile file, you will have to save the file and restart the game to see the effects. DO NOT open the settings menu during this process as it will cause your sensitivity value to be reverted to whatever it was when you last started the game.
The mouse currently in use will be at the top of this section of my PC setup sheet, also here on Gist.
Currently, as of the Open Beta build, I use the following:
FOV: In game, the FOV slider now uses horizontal FOV to be more consistent with other game engines, though Frostbite actually uses vertical FOV in code.
My Vertical FOV is 91°, which rougly maths out to 122° Horizontal FOV on a 16:9 display. The slider maxes out at 122°, but if you set it as 91° in PROFSAVE_profile, it will work and display 122 in the game settings menu.
Mouse DPI/CPI: 1600
DPI Deviation as explained and investigated by Ali at Optimum Tech
For mice with no discernible DPI deviation, I default to an in-game sensitivity of 0.004500 or 6 tick. This is twice my usual sensitivity, and is meant for hipfire, and comes to 37.98005cm for a 360° turn. When aimed, I have my coefficient set to 88.8% or 0.888888 in the config files, half the setting for 1:1 on a 16:9 display. This is my real sensitivity of 75.9601cm for a 360° turn, half the speed of the above, or an in game setting of 0.002250 or 3 tick.
To convert your sensitivity from other games into sensitivity in Battlefield 6, you will need a wonderful site called:
Mouse Sensitivity: Same Aim - Different Game.
Have fun!