Th body will need the HIGH GI Carbs post workout. The amount all depends in the type of training, the duration of the training, the intensity, and of course how much carbs you ate before this training session.
If your deposits are already full during the session you will not need much carbs. If you are almost emty(empty on glycogen) you willneed a larger amount. To do it simple the amount to be taken PW is oftenset to 50g protein 50g HI GI cabs.
For example. If you have been eating at 6 and to your workout at 9 in the evening, your traiing was intense and you worked out a big muscle group/groups like Quads. You will then need a high amount(40-90g dependingon a few factors) of carbs.
It the last meal before the workout consisted of 80g carbs and this meal was eaten at 8, the training was low intense and the musclegroup was biceps, you will not need this amunt of carbs.
The easiest way to do all this is to ignore all this, eat the same amount of carbs WPW and just smile. Before bedtime eat tons of protein and go to sleep. If you are hungry then eat. I wuld rather risk a little fatgain during the night with a carb meal before bedtime than risk insomnia because of hunger(I can not sleep if I go to sleep hungry).
As always, Keep it simple.