Personally, in ADS centric games (CoD, Apex Legends, Fortnite, Rogue Company), I set my ADS sens to default (or 1:1), and then i tweak my GENERAL (non-ads) sensitivity until my ADS 360 matches my hipfire sensitivity in Hipfire games (Counter Strike, Valorant, Overwatch).
EDIT: Unfortunately I don't think this website has a calculator for such things, so you just have to measure it with your actual movement. I.E. I know one full move across my mousepad in Overwatch/CSGO/Valorant takes me to about 6:45pm (200 degree turn), so in an ADS games I default my ADS, scope in on an iron sight, and match this movement! It works for me. might work for you!