i think 5 to 6 inches is normal size. so think 4 is a kinda small not really. i think my ex was about 4 OR 5 hard. its ok when its like that if you continue to date her and shes your only partener so she can fit to your size. i had to do that and even then sometimes it would be a lil bigger than him. and i was with him for 4 years.