Take a picture of your energy graph and change your displayed battery to percentage. Post a picture here that contains both.
You calculate by taking the recent Wh/mile (energy graph left side), multiplying by the projected range on (energy graph right side) and then dividing by your current battery percentage. Eg: (222 Wh/mile * 150 miles projected)/0.50% gives you 66.6kWh of 100% capacity.