fXenon look speed settings for different aspect ratios

[Bottletopman]

The FAQ has this little tidbit about making mouse sens equal on X and Y axes (kinda surprised this was an issue; I thought PUBG was the only game that had that bs going on):

If you have a 16:9 aspect ratio (such as 1920x1080 resolution) you may also make the mouse have the same speed on the x and y axes:

[Controls]
fXenonVertLookSpeed=1200.0000
fXenonHorizLookSpeed=1500.0000

Is there some sort of formula so we can figure out what values to use for different aspect ratios? My monitor is 16:10 so I'm not too sure what I should put.