$7,000 a Year in a Roth IRA at 25 vs 35: The $736,220 Head Start
Same contribution, same 7% return, ten years apart: $1,397,446 against $661,226. The gap decomposes into $70,000 you never deposited and $666,220 you never compounded.
Same contribution. Same return. One starts at 25, the other at 35, and they finish $736,220 apart.
That is the entire argument for starting a Roth IRA early, and it is not a slogan — it is arithmetic you can reproduce in about thirty seconds. Here it is, decomposed, along with the part the usual version of this comparison leaves out: what happens if you are already 35 and the decade is gone.
Two curves, same $7,000, same 7%
Assume both people contribute $7,000 a year — under the 2026 limit of $7,500 — earn 7% a year, and stop at 65. $7,000 a year is $583.33 a month.
| Start age | Years of growth | You contribute | Balance at 65 | Of which is growth |
|---|---|---|---|---|
| 25 | 40 | $280,000 | $1,397,446 | $1,117,446 |
| 30 | 35 | $245,000 | $967,658 | $722,658 |
| 35 | 30 | $210,000 | $661,226 | $451,226 |
| 45 | 20 | $140,000 | $286,968 | $146,968 |
Read the third column against the fourth, because that is where the argument lives. The 25-year-old puts in $280,000 and ends with $1,397,446 — 79.96% of the final balance is growth, not deposits. The 45-year-old puts in $140,000, ends with $286,968, and only 51.21% of it is growth. The later you start, the more of your own money you are relying on, and the less the market is doing for you.
Where the $736,220 comes from
The gap between starting at 25 and starting at 35 has two parts, and they are wildly unequal.
$70,000 is the contributions the 35-year-old never made. Ten years at $7,000. That part is intuitive — they simply deposited less.
$666,220 is compounding they never earned. Not on the money they skipped, but on everything after it, because the 25-year-old's balance is larger at every single point from age 35 onward and the difference compounds for another three decades.
Put those together and the arithmetic gets uncomfortable: the ten years of contributions a 25-year-old makes between 25 and 35 — $70,000 of deposits — are worth $736,220 by age 65 if they are never touched again. That is the entire gap, produced by a decade of $7,000 deposits and forty years of being left alone.
Can you buy the decade back at 35?
No. And the reason is worth seeing in numbers rather than accepting on faith.
To finish at 65 with the same $1,397,446 the 25-year-old reaches, someone starting at 35 with 30 years of growth would need to contribute $14,793.92 a year. The 2026 Roth limit is $7,500. The catch-up math requires roughly double what the law allows, so the shortfall cannot be closed inside a Roth IRA — the earlier decade is not purchasable at any price the rules permit.
What is purchasable is the next decade. The gap between starting at 35 and starting at 45 is $661,226 − $286,968 = $374,258, and between 25 and 30 it is $429,788. Every year of delay costs more than the year before it, which is the practical form of the argument: the cheapest year to start is always this one.
There is one thing that does improve with age, and it is easy to miss. At 50 the limit rises to $8,600. If the 25-year-old ran to 65 contributing $7,500 a year instead of $7,000, the finish line would be $1,497,263.
The 2026 rules you hit before the math does
Three numbers govern a Roth IRA in 2026, and two of them are traps.
The contribution limit. $7,500 if you are under 50, $8,600 if you are 50 or older. You cannot contribute more than your earned income for the year, and the IRS enforces a $200 floor on the worksheet — if the phase-out formula produces something under $200, you round up to $200 or contribute nothing at all.
The MAGI phase-out. This is the trap. For a single filer the ability to contribute directly starts phasing out at $153,000 of modified adjusted income and disappears entirely at $168,000. Married filing jointly: $242,000 to $252,000. Above the top of that range, a direct Roth contribution in 2026 is not allowed.
Here is what that costs. A 35-year-old with $160,000 of MAGI, single, is inside the phase-out. Their allowed contribution is not $7,500 — it is $4,000, and the calculator applies that reduced figure rather than the number you typed in. At 65 that account holds $377,843, against $661,226 for a 35-year-old at $7,000 a year below the phase-out. Roughly $283,383 of the difference was decided by a single income threshold, not by contribution discipline.
The five-year and 59½ rules. Qualified withdrawals are tax-free after age 59½ provided the account has been open at least five years. The earlier you open the account, the earlier that five-year clock clears — one more thing that does not wait for you.
Note that the phase-out is not a wall for everyone. A backdoor conversion — a non-deductible traditional IRA contribution converted to Roth — remains a legitimate route above the limit. It is worth one conversation with a tax professional, not a workaround to improvise.
What the order actually decides
Two people contribute the same $7,000 a year at the same 7%. One retires with $1,397,446 and the other with $661,226. Nothing about their discipline, their income, or their investment selection differed — only the order in which the same ten years were spent.
This is why the Roth discussion so reliably degenerates into "start early" without anyone showing the number. The number is $736,220, and it is made of $70,000 of deposits and $666,220 of time.
Run both start ages side by side in the Roth IRA calculator and the same projection starting at 35, then test your own MAGI against the phase-out with the phase-out example at $160,000. The full 2026 limit and worksheet detail is in our Roth IRA limits guide, and if you want to see what the same discipline produces in a taxable fixed-income account, the CD interest calculator runs the other side of that comparison.
Run your own numbers: Open the Roth IRA calculator at age 25 with $7,000 a year pre-filled