It was a couple years ago on maybe a FIRE subreddit, but in terms of expenses for aging parents who didn't save for retirement, or saved little and for the kids to pick up the expense, it works out to you needing 140% of what you think you'll need for your retirement to also help parents out. So = 100%(you) + 40%(them) of that for them. Luckily medicare helps out quite a bit, but long term insurances should be looked at and it may be worth a few bucks now to cover things later in their long lives. Originally social security was setup to give people dignity after retiring for a FEW years after 60. But now people are living a lot longer and simply are not of the generation to have planned for that. You too may live far longer than you expect. If you've made it past 30, you'll likely hit 80, if you make past that, it gives you something to think about.