How old is Yoshi/Splinter supposed to be in the FW series?
 

He's definitely older than Oroku Saki/Shredder and was even his master at some point, but he doesn't look like an old man per se. He doesn't have grey hair yet, his hair is pitch black, and he's still physically fit enough to fight bad guys occasionally. Oddly, he wears a cane after turning into a rat. As if the mutton has physically diminished him or something.

Shredder seems to be in his early 30s, so I'd say Splinter is maybe in his 50s at latest. He's definitely not 80 years old or anywhere near it.

He's middle aged, but not old, imo.

Thoughts?

50s does seem fitting, and some people at that age might use a walking stick due to health problems (Splinter was seen using it even before mutation).

I like how Splinter is Shredder's master and superior in the FW series rather than them being equals.

His Bio on the Arcade game says he's 30, but I'm not sure that's considered canon. For that matter, his bio on the action figure card says "unknown."

Guess I've always kinda assumed around 50ish.

I’d say mid to late forties.

True but I think it's safe to say Yoshi was a very healthy man, even though he ended up living as a homeless man in the sewers. He's not wearing a cane or walking stick during the flashback in the first episode.

I think he's not that supposed to be that old but they kinda went with it to make him fit more the Mr. Miyagi stereotype. It's always such a clash between him and Shredder. Splinter talks in that old sage like 'hmm this is most strange' while Shredder just wisecracks as if he's been a New Yorker all his life. He had a bit of a stronger accent in the first season but that went away quick.

Human Splinter is seen using a walking stick when Shredder talks about how he followed him to New York in the 2nd episode, and he uses it again when he becomes human again in 'Splinter No More'.

Agreed though, it seems odd for a man of his build and fitness needing a walking stick. If he does have some hidden health problems though, it would explain why he often stays in the lair and doesn't accompany the turtles too often in their adventures.

Willy Wonka was an acrobat and he had a walking cane, but just for style:

It;s honestly hard to say as we're not sure how long the Turtles and Splinter lived and trained in the sewers prior to them saving April from Shredder's gang. The movies say 15 years and it's made clear there that Splinter's time is running short. I know, different situation. The cartoon never reallly says how long they were down there, but ninja training doesn';t happen overnight and Splinter could still best the likes of Shredder and even chronos near the end of the show.

Is it assumed that 15 years had passed from them being mutated until present day Turtle Tracks? In the flashback to Japan, Saki was a student and Yoshi was the teacher. So one could pretty easily presume that Yoshi is 20 or so years older than Saki. And Shredder did refer to Splinter as "old" on multiple occasions during the shows run. So if we do assume that 15 years had passed, perhaps that might makes Splinter in his late 50's, and Shredder in his late 30's?