To simplify input for those who play with custom aspect ratio, the calculator now has native support for this.
If you don't use a custom aspect ratio, just leave it at "Native"!
This means that you enter your monitor's resolution, then select the aspect ratio you use.
Stretched is the aspect ratio stretched out to the entire resolution of your monitor.
Black bars is either black bars on the sides, or letterbox i.e. black bars on top and bottom.
Important: Changing aspect ratio does not necessarily change anything in your calculation! 360 distance will always stay the same, and if you're using a vertical matching method stretching horizontally does not change anything and vice versa.
The "Actual FOV" in the output will show you the FOV for your aspect ratio.
For instance those who play CSGO with 4:3 stretched on a 1920x1080 monitor do like this:
If you play with black bars, select this:
If you're on an ultrawide monitor and there's a game that does not support 21:9 but maxes out at 16:9, do this:
Likewise on a 16:10 monitor with a 16:9 game (so you have black bars on top and bottom):