I know this sounds stupid but how old is Jasper? in human years. like physically? i can't find it anywhere!

if Ты go on to the new moon page then go on to the Статьи theres one called the medow in edwards perspective. click on there and go to еще Статьи by brown_x_eyes and on the секунда page theres a full biography for most of the characters, incase Ты need еще information about any one else.
but this is part of what it saids for jaspar-

Jasper was turned into a vampire in 1863 by a vampire named Maria when he was 20 years old.

i havent edited this at all. ive just copied part of it. hope this helps.

he's 20....

check out www.twilightlexicon.com under character bios