The Cost of Waiting: Starting to Invest at 25 vs. 35 vs. 45

The Numbers

Contributions over 40 years total $144,000, over 30 years $108,000, and over 20 years $72,000. The rest of each final balance is investment growth: $643,000 for the 25-year-old, $258,000 for the 35-year-old, and $84,000 for the 45-year-old. The early starter earns far more from growth than from their own contributions, whereas the late starter's balance is mostly deposits.

The assumptions are 7% annual return compounded monthly, steady contributions, no taxes or fees, and no change in the contribution amount.

Catching Up Is Expensive

To match the 25-year-old's $787,444 starting at 35, a person would need to invest about $645 a month, more than double the $300. Starting at 45 would require about $1,500 a month. Catching up gets harder each year you delay, because there is less time for compounding. That does not mean it is too late to start; it means that every year counts and that the best time to begin is as soon as possible, even with a smaller amount.

A modest amount invested at 25, such as $100 a month, grows to about $262,500 by 65, which is more than $300 a month would produce starting at 45.

Caveats: Returns Are Not Guaranteed

A 7% average annual return is an assumption. Actual returns vary a lot from year to year and over decades; stocks can lose 30% or more in a single year, and there have been long periods of weak returns. A real-world plan should consider inflation, fees, taxes, and risk. Over long periods, however, a diversified stock portfolio has historically delivered positive real returns, which is why time in the market has been rewarded. The cost of waiting is not an artifact of this specific rate. At 5%, the advantage of starting early is smaller in absolute terms but still large in proportion.

What to Do If You Started Late

Increase your savings rate as much as you can, take advantage of employer matches and catch-up contributions available after age 50, delay retirement a few years to add contribution time and reduce the years you need to fund, and consider part-time work in retirement. Reduce costs, which lowers the target. Even starting at 45 or 55 can make a major difference compared with not starting at all, and a late start is better than none.

What to Do If You Are Young

Pay off high-interest debt, build a small emergency fund, capture any employer match, and automate investments in low-cost diversified funds. Increase contributions with each raise. Do not wait to feel wealthy before starting: small, consistent amounts at a young age are worth more than larger amounts later.