ideally you want to match the fov exactly
https://www.mouse-sensitivity.com/?share=79d2d28cc478d28f711c0f4f56239fae
when you play stretched in both games you should be able to have 73.74 vertical fov with 90 hor
Try something like this (adjust resolution, DPI and FOV etc according to your settings):
https://www.mouse-sensitivity.com/?share=1ff23e5ca53c74e4ab27fd8aea9a9254
This game was removed from the calculator since the sensitivity is extremely inaccurate. There's a lot of acceleration and smoothing, and impossible to get a consistent result.