Unhappy internal storage space left 1.9 gb

i have a galaxy s4 i9500. after i root it with cf auto root and flash cwm 6.0.4.5 and flashed it with wanamlite, my internal storage drops to 1.8 gb left. the same thing happen with cm 10.2 Is that suppose to happen? please provide me with some answers and insights. pleaseeee...