How to use it
Zoom in on your gun on the tactical map, right-click and pick Mark Coordinates. The pair lands in chat, so you can copy it straight out. Paste it into the first box, repeat on the target, and the range appears. Both fields accept whatever form you paste — x98.52, y110.39, 98.52 110.39 or 98.52,110.39 all read the same.
The math behind it
This is the distance formula, the one your gunnery guide writes as A² + B² = C². Subtract the target X from your X and square it. Do the same for Y. Add the two squares, take the square root, and you have the distance in coordinate units. One coordinate unit is 100 metres, so the range in metres is that distance times 100. Every one of those steps is printed under the readout, so you can check it against your own calculator.
Plenty of guides tell you to read the first three digits of the square root instead. That gives the same answer while you are under 1000 metres and quietly breaks above it — a 12.34 unit shot is 1234 metres, not 123. Multiplying by 100 does not have that ceiling, which is why the long guns still read correctly here.
What this does not do
Range only. No azimuth, no elevation in mils, no time of flight, and no correction for the height difference between you and the target. Take the range, dial it into your gun's firing table yourself, and treat the first round as a ranging shot.
Questions
Does it work for both the mortar and the artillery?
Yes. The distance between two points does not care what is firing. What changes is whether your weapon can actually reach that range, and you check that against your own firing table.
Do I need to install anything?
No. It runs in the browser, keeps nothing, and sends nothing anywhere. Leave it open on a second monitor or a phone.
Why is my answer one metre off from a video guide?
Rounding. Guides that trim digits at each step lose a little every time. A metre is far finer than where the shell actually lands, so it makes no practical difference.