What does waiting 5 years to start investing cost?
About $123,000 if you put aside $300 a month at a 7% return over 30 years.* Starting on time ends near $366,000; starting 5 years late ends near $243,000. Only $18,000 of the gap is contributions you skipped; about $105,000 is growth those early dollars would have earned. To catch up after 5 years you would need about $452 a month instead of $300.
Cost of waiting, $300 a month at 7% over 30 years*
| Wait | End amount | Total cost | of which lost growth |
|---|---|---|---|
| Start now | $365,991 | - | - |
| 1 year | $337,850 | $28,141 | $24,541 |
| 3 years | $287,132 | $78,859 | $68,059 |
| 5 years | $243,022 | $122,970 | $104,970 |
| 10 years | $156,278 | $209,713 | $173,713 |
The skipped contributions are only $3,600 per year waited. The rest is growth those contributions would have earned over the remaining years.
*Arithmetic on a fixed 7% return with growth compounded on the amount put aside, no taxes or fees. 7% is a common long-run planning assumption for a stock index fund, not a forecast or a promise.
Worked example
- Plan: $300 a month for 30 years at a 7% return, the default above.
- Start now: the amount grows to about $365,991. Total paid in: $108,000.
- Wait 5 years: 25 years of growth instead of 30, ending at about $243,022. Paid in: $90,000.
- The gap is $122,970. You skipped $18,000 of contributions; the other $104,970 is growth those first 60 contributions would have compounded into.
- To still reach $365,991 after waiting 5 years, you would need about $452 a month for the 25 years that remain.
- Real returns move around and fees matter. See what a 1% fee costs over 30 years.
Fee Leak Calculator: what a 1% fee does to the same growth
The history of the 401(k): from Studebaker to who owns the risk
Sources
- The 7% default is a planning assumption, chosen by us and labelled as one. It sits near the long-run inflation-adjusted return of the US stock market as tracked by Damodaran's historical returns data (NYU Stern), retrieved October 20, 2026.
This tool runs arithmetic only. It has no market data feed and makes no prediction.
How this is calculated
Each amount put aside grows at the chosen return for the years it stays invested. Starting later removes your earliest contributions, which are the ones with the most years to compound. The catch-up figure solves for the higher regular amount that reaches the same end total over the shorter time.
Common questions
Why are the early dollars worth so much more?
Because compounding multiplies by time, not by effort. The first $300 grows for all 30 years; the last $300 grows for one. Remove the first 60 contributions and you remove the longest growth runs.
Is 7% realistic?
It is a planning assumption, not a promise. Long-run US stock returns have averaged near that after inflation, but any single period will be higher or lower. Slide the return to see how the answer moves.
Does this include taxes or fees?
No. It is pure growth arithmetic. Fund fees alone can cost six figures over 30 years; the Fee Leak Calculator shows that part.
What if I can only start small?
Starting small now beats starting bigger later in most cases, because time in the market does the heavy lifting. Put your own amount in above and compare 0 years against your realistic delay.
Is this financial advice?
No. It is a calculator for education. It does not say what you should invest in or when.