"Jesus, when he began his ministry, was about thirty years of age" (Luke 3:23). It is presumed that his ministry lasted about three years, inferred from historical events and annual feasts that the Gospels say he observed.
So insofar as he began when was "about thirty," it also stands to reason that he was crucified at "about" 33. Given that we don't know precisely when he was born or when he was crucified--also only "about"--it's plausible that he could have been any age in his early to mid-30s.
Luke gives a ballpark figure, and that's really all we need. Nothing in the Gospels hinges on Jesus's age.
One of the early fathers, I forget which, believed he was closer to 50, based on John 8:57: "You are not yet fifty years old, and have you seen Abraham?" Which I think kind of misses the point. Abraham was 2000 years in the past, and Jesus wasn' t even 50, let alone 2000, or so they thought.