Paste the two coordinates and get the range to set. Your first shell lands on the target instead of telling the enemy where you are.
Paste both coordinates above. Anything containing two numbers works, so you can paste the whole chat line without tidying it up.
The method is SwoleBenji's, published on Early Access launch day, and he asked for exactly this on camera: “hopefully someone out there makes a website that can calculate, you just paste it in and it calculates it for you”. So here it is. The full walkthrough is in our write-up, including how to line up the direction, what each tube reaches and the three shell bombard.
Nothing on this page is a statistic. Both numbers come from your own game and the rest is arithmetic, which is why it shows the working: you should be able to do this without us when the tab is closed.
On the map, right click the spot and choose Mark coordinates. That writes them into the chat box. Select all with Ctrl and A, copy with Ctrl and C, then paste here. Do it once for your mortar and once for the target.
Map coordinates are in hundreds of metres, so a distance of 4.12 between two points is 412 metres on the ground. It is the step most people miss, because a calculator gives you 4.12 and that looks like an answer already.
Yes. The maths is the same for any indirect fire, only the reachable range differs: the mortar covers up to about 700 metres and the artillery runs from about 750 up to 2,630. Those bounds are one creator's readings off the launch build rather than published figures, so treat them as a guide.
Yes, for direction. Middle click the target on the map to drop a white diamond, swivel the tube until the diamond is on screen and centre your aimer on it. This page gives you the range to set on the RNG ladder, which is the half you cannot eyeball.