i was pissed of using website calculator so there is my new mod who add a balistic calculator ingame on every mortar, when u click on select target it open the map u click where u want to land a shot it return on balistic calculator u click on calculate it show every info that u need to set up the shot u can click on PIN to add a second layout on the right of your screen to keep your info when u sit in the mortar if u want to delete this pin u can UNPIN in the balistic menu or by walking away from 50m it will delete automaticly
u can also sit in the mortar directly and look the bottom of the mortar to open the balistic calculator 
--------------------------------------------------
Its the V1 of the project be kind 
for the V2 i will  try to add a mortar shell tracking option to see where your projectil land on the map and upgrade the calculator layout for something less ugly
for the V3 i will try to add an auto moving option for the mortar i dont know if it possible but lets see

Mortar Calculator

look at the bottom of the mortar open ballistic computer
select target > click on the map where u want to hit > calculate > Pin >enter in mortar >enter values of the HUD > exit from mortar and shoot

Mortar Calculator

1.0.4

1.0.3

1.0.2

1.0.1

1.0.0