Default low memory - storage space running out

i been having this storage issue, even though i dont have any pictures/video/songs in my internal memory plus i deleted my apps it keeps on saying low memory, on top of this to check the device storage when going into setting, it keeps on saying calculating and i have waited for like 15min but still says calculating. i had this problem 1 month ago and i factory restored everything and started again now the issue is back.....