Does anyone know how to calculate the total Delta V I would get from my Ion engines with the spesific amount of Xenon Gas I got and the total mass the ship has. I know MechJeb does this for me, but I forgot to attach it to my ship, so I wanna learn how to do it manually so I can save time. (My ship has 21.43t Mass and 27200 Xenon Gas) Thanks in advance.