Mouse focal length sensitivity scaling conversion?

[brak obama]

I currently have this setting on and I know it changes the sensitivity based on FOV. My sensitivity is at 45 and my ADS sensitivity is perfect with the scaling on. How can I calculate what my sensitivity would be to match the ADS speed with turning this option off? I want to turn this setting off because the hip fire sensitivity is too fast for my liking and I would like to have it 1:1 to my ADS.