Is investing $100 a week enough to fund retirement? / 85
Lots of retirement questions sound simple on the surface.
Is investing $100 a week enough?
Am I saving enough?
Will I be okay?
The challenge is that none of those questions has a one-size-fits-all answer. Your retirement timeline, spending goals, investment returns, and other income sources all play a role in determining what "enough" actually means.
Rather than focusing on a single dollar amount, this episode walks you through a practical framework you can use to evaluate your own retirement plan. You'll see how investing $100 a week can grow over time, learn how to estimate the amount you'll need to retire, and understand why flexibility matters just as much as consistency when you're investing for the long term.
Episode highlights
[00:00] Is investing $100 a week enough to retire? The five factors that determine the answer.
[02:30] How $100 a week can grow over 20, 30, and 40 years — and why time is your biggest advantage.
[06:30] A simple way to calculate your retirement number using your expected annual spending and the Rule of 25.
[08:00] How Social Security and other income sources can reduce the amount you need to save on your own.
[09:30] The retirement expenses people often forget to factor in — and the ones that may disappear altogether.
[11:30] Why your retirement contributions don't have to be perfect to keep making meaningful progress.
The five factors that determine whether $100 a week is enough
There isn't a universal retirement savings number that works for everyone. Two people could invest the exact same amount every week, and one person could have enough while the other struggles in retirement.
Everything depends on the following five factors:
How much you've already invested
How many years you have until retirement
What you're investing in
How much you'll need to spend each year in retirement
Other retirement income you expect to receive, such as Social Security or a pension
Out of all of these, time is one of the biggest advantages you can give yourself. The longer your investments remain in the market, the more opportunity compound growth has to work in your favor. That’s why, if you take one thing away from this blog post or podcast episode, it’s to start investing ASAP.
What investing $100 a week can grow into
To show how powerful time can be, we looked at several scenarios using a 7% annual return. This reflects the stock market's historical average real return, accounting for inflation.
In the following examples, assume you start with $0 invested. Here’s where you’d end up with a weekly $100 investment:
After 20 years
Total contributions: $104,000
Estimated balance: ~$213,176
Investment growth: ~$109,000
After 30 years
Total contributions: $156,000
Estimated balance: ~$491,196
Investment growth: ~$335,000
After 40 years
Total contributions: $208,000
Estimated balance: ~$1,038,000
Investment growth: ~$830,000
The longer your money stays invested, the less of your final balance comes from your own contributions and the more comes from investment growth.
That's why starting earlier can have such a dramatic impact, even if you're investing just a small amount of money.
How to calculate your retirement number
Knowing what your investments could grow to is only half of the equation. You also need to estimate how much you'll actually need in retirement.
One simple way to start is by estimating your expected annual spending during retirement.
Picture yourself retired. Where do you live? What do you do for fun? How’s your health? Use this picture to create a mock budget estimating how much retired life will cost.
From there, you can use the rule of 25 to estimate how much money you need to be able to retire comfortably. All you do is multiply your expected annual expenses by 25 to get a good estimate.
For example, say you plan to spend about $60,000 annually in retirement. Using the rule of 25, this means you should have $1.5 in your portfolio by the time you retire.
$60,000 × 25 = $1.5 million
At first, that number might feel overwhelming. But remember: retirement savings typically accumulate over decades, not overnight, and investment growth does a lot of the heavy lifting for you.
Don't forget about other retirement income
One mistake people often make is assuming they'll need to fund every dollar of retirement spending from their investments.
For many people, that isn't the case.
Social Security, pensions, and other retirement income can reduce the amount your investment portfolio needs to generate.
For example, say you plan to receive $2,000 from Social Security each month. (That’s $24,000 per year.)
Using the scenario above, if you need $60,000 in retirement, you only have to supply $36,000 of that — Social Security will provide the rest.
Using the Rule of 25 again:
$36,000 × 25 = $900,000
That's a much different target than $1.5 million.
Tip: You can create an account through the Social Security Administration to see your own projected benefits based on your earnings history, giving you a more personalized estimate as you build your retirement plan.
Make a plan, but don’t worry about perfection
When estimating retirement expenses, remember that some costs may decrease while others increase.
You may spend less because:
Your mortgage is paid off.
Your children are financially independent.
You're no longer saving for retirement.
On the other hand, you may spend more on:
Healthcare
Travel
Charitable giving
Hobbies and experiences
Your retirement budget should reflect the life you actually hope to live, not an arbitrary number.
It's also worth remembering that investing doesn't have to look exactly the same every year. For example, you might be able to sock away lots of money while young and single but have to pull back on investments while paying for childcare. That's totally normal, and totally okay.
Rather than striving for perfection, just try to be consistent over the long run. Increase your investments when you're able, scale back when necessary, and keep moving forward. Retirement planning is a decades-long process, and flexibility is part of making a plan that lasts.
TL;DR
Investing $100 a week may be enough for retirement, depending on your goals, timeline, and expected expenses.
Time and compound interest often have a bigger impact than trying to invest huge amounts all at once.
Use the Rule of 25 to estimate your retirement savings goal based on your expected annual spending.
Factor in Social Security and other retirement income before deciding how much you need to save.
Progress matters more than perfection. Adjust your investing as life changes, and keep building toward your long-term goals.
✨ Resources ✨
SSA.gov — My Social Security account
This content is for educational purposes only and should not be considered personalized financial, legal, or tax advice.
