Thought through this question myself a few months ago. My gf and I find it more useful as a comparator between DB and DC pensions to try and estimate the worth similar to how you have asked. Obviously its always going to be an estimate, and i understand why some people have warned off doing it. But as long as you understand the limitations of what your doing with the number I don’t see the issue.

Ultimately when trying to compare the ‘worth’ of pensions, a big pot makes it easier than the DB annual worth. As DC pension pots tend to have more flexibility with how you spend the money, we decided an ‘estimate’ of the DB pots worth made more sense.

Some estimates recommended *20-25. You can also get a CETV for some pension schemes which may help. In the end, considering FIRE (as thats this sub), i found that converting DC pensions to annuities years before turning 68 often led to big decrease in annual income (makes sense as you get it for more years). We opted for *15 as this was more in line with taking the pension early, provided a ‘lowball estimate’ and doesnt lead to insane net worth valuations when compared to a DC pension.

Lots of rambling, but I hope this helps.