Also you must take into consideration that they use the camera angels very effectively and small, female pornstar hands to make it look even bigger.
Not saying they are small but they do what they can to make things look bigger than they really are. Just take the white male pornstar Jonny Sins as an example, on his adult entertainment bio it says he’s like 9 inches if I remember correct though I’ve seen pictures proving he’s only 7,5 inches. I even think he’s admitted that himself.