Trying to nail down a specific number seems like a fools errand that will output a number just below whatever age before people start picking up weight and qualifiers that make them less desirable (like "single mother"). Sure you get a number but that number isn't going to be very useful for applying to anything.

The important point is that men usually have it worse (than women) at a young age and potentially have it better at an older age.

Somehow we have to compress that into something short enough to share.