Financially speaking, what might happen if you had 100 years of excellent health?

Published: 2023-09-19

Author: Ben Maddox

Financially speaking, what might happen if you had 100 years of excellent health?

It may be born from reading too many fantasy novels, but I wondered what might change if someone lived hundreds of years with 100 years of it being with excellent health. You may have seen calculators that help with retirement or “long-term” plans. But what if you take that to the extreme?

In this article, I wanted to try to think through some differences that occurred with a long life. There are of course many aspects of life, but I’m limiting it to financial. Imagine that you have a fairly middle of the road household income in the U.S. Real Earnings News Release - 2023 M07 Results ( As of 9/13/2023, average weekly earnings were $980.20 or about $50,970.40 annually. We’ll go through that amount with reasonable current day calculations and a hypothetical extended life.

I’ve seen articles for retirement recommend taking about 15% of your income and setting it aside for retirement. How much money should I save each year for retirement? | Fidelity I know many struggle to hit that amount, but having a baseline is needed for this exercise. I’m going to make an assumption that someone making close to the average is likely to have college experience or a few years of work experience right after high school. Hopefully getting to a point where money can be set aside starting around age 25.

If someone is working and setting aside around 15% from the ages 25 to 65, that’s 40 years. It’s a rough estimate that we’re working with but it should still give an idea of the scale. With the compound interest calculator Root Beer Math Compound Interest you plug in a few numbers. 0 for the starting principal, $7,645.56 for annual additions, interest rate of 5% (rough inflation adjusted rate), 40 years. You can see that would get you around $923,581.92 at the end of that period.

With $923,581.92 accumulated, if you want to withdraw 4% of that per year for the next 30 years, that would give you $36,943.28 per year. While not as much as the the salary, it could still provide a modest lifestyle during requirement.

Now for the fun part. What would happen if instead of 40 years of earning money and investing for retirement, you could save for 75 years? Age 25 - 100 instead of 25 - 65. Again, this is with the idea that people could be living very healthy lives for 100 years. Well, let’s assume that the person continues their same level of earning but just lengthens it. And we also want to assume that they will live a lot longer than 30 years once they stop working.

If you change the number of years from 40 to 75, the total now grows significantly! $5,785,041.40 could be set aside. We almost double the working years, but it have over 6 times the total money at the end. That is a huge difference! Taking out 4% of that for a 30 year period would be $231,401.65 per year. Or to make it last longer than 30 years, a 3% withdrawal rate could get you $173,551.24 per year.

This is a hypothetical that takes a very extreme approach to investment time. Can you imagine the difference it would make to have roughly triple your income in retirement? I hope that it is interesting about how much time makes a difference for investing. And it also gives very interesting ideas of what society could be like if we find ways to greatly improve our health or our children’s health in the future. Thanks for taking the time to read through my financial musings.