Originally Posted by CM3: World Material, p.133I think it's probably pretty well-accepted (especially with how it's portrayed in the anime scenes and all, I don't exactly recall if it's mentioned at length in the VN) that he dies shortly after signing the contract, so "late twenties to early thirties" would be the span for his death as well.Originally Posted by CM3: World Material, p.133
Since we know that Archer doesn't come from one of the FSN routes, but a "variation of Saber's route" (CM3, p.130-131; UBW Animation Material II Q&A) you can perhaps assume that the Shirou that becomes Archer never encountered UBW before that and thus he would take 20 years to master it, which puts him at roughly 38 years of age. Of course, there's some leeway here, as well.Originally Posted by Comptiq 2007-12 issue - Fate Dojo Q & A
Safest bet is "in his thirties".