Should I post this? I’m sleep deprived, why not?
Featuring my recent re-read of Chaos Rising and notes on this topic.
SO. We have two important clues: 1) Thrawn meets Anakin close to the end of the war (it is implied Ahsoka has already left the order, I believe), ~19 BBY. 2) Thalias, on joining the Springhawk shortly before this incident, muses that it’s been two decades since she’s been in the military, which presumably was her last voyage shipping Thrawn between Rentor and Taharim Academy: his first space trip, when he became a cadet.
We don’t have enough for an exact age, so I’ll consider the YOUNGEST he could possibly be (but he’s probably older) and the OLDEST he could plausibly be (but he’s probably younger).
Thalias sees Thrawn as “young,” which, her being 13, could very well be somewhere around 16 to 18 (high school kids felt SO OLD in middle school), and he gives off teenager vibes in his conversation with Thurfian. We don’t know when military training starts for the Chiss, but I feel like it’s young; 18 (college age) is reasonable, but considering the Chiss emphasis on getting Ruling Family attention from even a young age, 14-16 (high school age) seems plausible. Thus, 14 is the absolute YOUNGEST he could possibly be when meeting Thalias, presumably an older-looking 14 since he still has to crouch to meet Thalias’s height. The OLDEST he could plausibly be would be maybe 22 at a stretch (graduating college/graduate school age). A more reasonable age would be around 16-18 (finishing high school or overachieving college student).
Now, Thalias’s musings on her “two decades” without military timing could be an exaggeration; I would use “oh, about 20″ for a range from about 18 to 22.
So, the YOUNGEST Thrawn could possibly be in 19 BBY is (14+18=) 32! Which would put him at 51 at time of space-whaling.
The OLDEST Thrawn could plausibly be in 19 BBY is (22+22)= 44, which would put him at 63 at time of space-whaling.
A more reasonable estimate I would say would be around (16 or 18 + 20)= 36 to 38 in 19 BBY, which would put him at 55 to 57 at time of space whaling.
No matter what, he’s at least 60 by the time the Mandalorian comes around (9 ABY).
This concludes an estimate of Thrawn’s age.