I have this information from the Ninjago wiki.
What is confirmed:
S1:
Lloyd: 9-11 (confirmed by Tommy)
Nya: Not younger then 14 (confirmed by Tommy)
Kai: 16+, two years older then Nya (confirmed by Tommy)
Jay and Cole: proably between 14,5 and 17.
Zane: 40+ (confirmed)
Present:
Jay, Kai and Cole are in their late teens, so i would say between 18 and 20
Nya: 16-18
Lloyd: max. 11-13
Zane: 100
Zanes body: 60
This is is not my opinion but is (pretty much) confirmed.
