i assume you mean as in your increased earnings will no longer pay the expense. The never too late crowd is thinking of school as a pure 'fun' activity which is a valid way to look at things but if you don't like school isn't for you and that is how I'm choosing to interprut your question.

the question is never answerable unil after the fact: I can calculate after you are dead. However I went to school with someone who went right to college, a mistake because he died in an accident at 21. Other people get mental decline in older years and so it is too late when they are no longer able to learn.

you can retire at any age when you have enough savings, but some people find it boring and will continue to work anyway - if this is you it can be worth it even if ecconomics don't work out if you get a job you like (or perhaps one that by not wearing on the body you can do longer)

many jobs pay for your schooling. if this applies the only quesntion is will you have to remain at the job longer than you want to afterwards.

if paying for your own schooling you can calculate the expected earnings after and compare to the cost to make a decision.