How do I calculate cost per mile on EV

All agreed that doing this on ICE car is easy

Having purchased and EV a few weeks ago, I have taken the mileage when I purchased and charged a couple of times. My BMW App (for the i3s) shows many times, "Kwh' charged and the cost(which I have entered depending on if I am charging at home or station).

So I would like to calculate cost per mile driven so far considering I still have to take into account the %charge still left on car

Thanks