We've talked about the length of the penis in its ordinary non-erect state, but how long should it be when it's erect?Interestingly, most penises are very much the same size when erect.
- The man whose non-erect penis is smallish will usually achieve about a 100 per cent increase in length during sexual excitement.
- The man whose non-erect penis is on the largish size will probably manage about a 75 per cent increase.
- This means the great majority of penises measure between 15cm and 18cm (6-7 inches) when erect, with the average figure being about 16.5cm (6.5 inches).
- The vagina of a woman who hasn't had a child is only 7.5cm (3 inches) long when she's not sexually excited. The figures for women who have had babies are only slightly different.
- Even when aroused, a woman's vagina usually extends only to a length of about 10cm (4 inches).