Most people know that starting to invest earlier is better. What they don’t know is how much better — and the actual dollar figure tends to stop people cold.
If you invest $400 a month starting at age 28 and retire at 67, at a 7% average annual return, you’d end up with roughly $975,000. If you start the exact same $400 a month at age 33 instead — just five years later, same monthly amount, same consistent return — you’d end up with about $668,000. The gap between those two outcomes: $307,000. For a delay that probably didn’t feel like a conscious decision at all. It felt like life: a job change, student loans, a move, a lean year.
Here’s what makes that number hit harder. The difference in total contributions between starting at 28 versus 33 is only $24,000. That’s 60 months of $400. The other $283,000 of the gap comes not from missed contributions but from missed compounding time. When you delayed, you didn’t just skip five years of deposits. You removed those contributions from a 39-year compounding runway and put them on a 34-year one. That five-year difference, applied to every dollar invested, is where the $283,000 comes from.
The Numbers at Every Starting Age
The table below shows what $400 a month — consistently invested from a given starting age until 67 — produces at a 7% average annual return. These figures assume continuous contributions and steady returns, which real markets don’t deliver in a straight line. The 7% figure is a reasonable long-run estimate for a diversified stock index portfolio, widely used in financial planning projections. Verify any assumptions with a financial planner or fee-only advisor for your specific situation.
| Start Age | Years Investing | Total Contributed | Portfolio at 67 (7% avg. return) |
|---|---|---|---|
| 25 | 42 years | $201,600 | ~$1,217,000 |
| 28 | 39 years | $187,200 | ~$975,000 |
| 33 | 34 years | ~$163,200 | ~$668,000 |
| 38 | 29 years | $139,200 | ~$450,000 |
| 43 | 24 years | $115,200 | ~$298,000 |
The pattern is not linear, and that’s the important part. Going from age 25 to 28 costs $242,000 in final portfolio value. Going from 28 to 33 costs $307,000. Going from 33 to 38 costs $218,000. The earlier blocks of five years carry a larger dollar cost than later blocks, because the early contributions have the longest runway for compound growth. A dollar invested at 25 has 42 years to grow. That same dollar invested at 33 has only 34 years. The difference in final value for that one dollar — at 7% annual growth — is meaningful enough to change retirement outcomes by hundreds of thousands of dollars in aggregate.
What the Five-Year Gap Actually Looks Like Per Dollar
Here’s a useful way to see the cost at the individual contribution level. A single $400 investment made at age 28, growing at 7% annually, reaches roughly $5,600 by age 67. That same $400 invested at age 33 instead grows to about $4,300 over 34 years. The cost of delaying that one $400 deposit by five years: $1,300. Now apply that $1,300-per-deposit loss across 60 monthly deposits — all the contributions made between 28 and 33 — and you arrive at the $307,000 gap. It’s not one big missed opportunity. It’s 60 smaller ones, each quietly compounding in the wrong direction.
This framing matters because it shows where the damage actually accumulates. It’s not the contributions made at ages 32 or 33 that hurt most when delayed. It’s the contributions that would have been made at 28 and 29 — the ones with the longest remaining compounding runway. The earlier in the sequence a delay occurs, the higher its eventual cost. That’s why financial planners emphasize starting at all over starting optimally. Getting money into the account — any amount — at 28 rather than 33 is worth far more than the contribution size suggests.
Is It Too Late to Catch Up at 33?
No. But it helps to be precise about what catching up actually requires. To end up with the same ~$975,000 as someone who started $400 a month at 28, a person starting at 33 needs to contribute approximately $585 a month — not $400. That’s an extra $185 per month, every month, until retirement at 67.
For many households, $185 a month is achievable — especially if it comes from a pay raise, a debt payoff that freed up cash flow, or redirecting discretionary spending. The point isn’t that catching up is easy. It’s that the math is specific, and specific numbers are easier to plan around than abstract feelings of being behind.
The starting account matters too. Whether to use a Roth 401k or a traditional 401k for those catch-up contributions depends on your current tax bracket and where you expect to land in retirement — and getting that decision right can be worth tens of thousands of dollars over a 34-year horizon. Someone in the 22% bracket today who expects to remain there in retirement might find Roth and traditional contributions roughly equivalent. Someone who expects a higher bracket in retirement has a clear incentive to prioritize Roth now. Neither answer is universal.
What is universal: capture any available employer 401k match first, at any contribution rate. A 50% or 100% employer match on matched contributions is an immediate return that no market investment replicates. After the match, a Roth IRA funded to its annual limit is typically the next step. Contribution limits for Roth IRAs adjust periodically — verify current limits at irs.gov before setting your annual target, as they’ve changed multiple times in recent years.
What If You’re Not at 33 — You’re at 43?
The math gets steeper, but it doesn’t become hopeless. A 43-year-old contributing $400 a month through age 67 builds roughly $298,000 — a gap of $677,000 compared to someone who started at 28 with the same monthly amount. Fully closing that gap by retirement would require contributions in the range of $900 to $950 a month starting at 43, which is a meaningful stretch for most households.
The more realistic approach for someone starting in their 40s is a combination of four things: higher monthly contributions than $400, a slightly later retirement target, lower monthly income needs in retirement (paid-off house, smaller recurring expenses), and Social Security income supplementing portfolio withdrawals rather than replacing them. Understanding how much you specifically need saved by 45 to support a given monthly income in retirement is more useful than chasing a single abstract number — because the answer depends entirely on your expected expenses and income sources.
Once you reach 50, the IRS allows meaningfully higher annual contribution limits for 401ks and IRAs through what are commonly called catch-up provisions. How much extra you can contribute and how those additional contributions compound over a 10-to-15-year horizon is worth understanding before you hit 50, because the window opens faster than it feels like it will. Those catch-up limits have also changed in recent years — verify current amounts at irs.gov.
Which Account to Prioritize When Starting Later
The account structure you choose doesn’t determine how much money earns inside it — the market does. But it determines how much of that growth you keep after taxes, which is a different and equally important question.
For a late starter in their late 20s or 30s who expects to be in a similar or higher tax bracket in retirement, a Roth IRA is typically the right starting point: contributions go in after-tax, growth is tax-free, and qualified withdrawals in retirement are tax-free. For someone at 33 who has fewer compounding years than an earlier starter, keeping all of that growth inside the account rather than paying income taxes on withdrawals in retirement has compounding implications of its own. A $668,000 Roth portfolio generates a fundamentally different retirement income than a $668,000 traditional IRA, because every withdrawal from the traditional IRA is taxable at ordinary income rates.
The sequence most financial planners recommend: 401k contributions up to the employer match → Roth IRA to its annual limit → additional 401k contributions. That order maximizes the employer match (which is free money), prioritizes tax-free growth, and then continues building pre-tax contributions at the margin. Individual circumstances — self-employment, no employer plan, high income above Roth eligibility thresholds — change the order. Verify your specific situation with a tax professional or fee-only financial planner.
The One Move That Makes Everything Worse
Continuing to wait. The table above shows the cost of a five-year delay at the start of the investing timeline. What it doesn’t show directly is how that cost scales when the delay isn’t five years but eight or twelve. Every additional year of delay is a compounding problem: not just the contributions missed, but all the growth those contributions would have generated for the remaining decades. The later the start, the more dramatic the monthly contribution increase required to compensate — and the harder that increase is to sustain.
The practical implication: starting at $150 or $200 a month at 33 beats starting at $400 a month at 36 in nearly every scenario, because even small contributions entered into the account early have more years to compound than larger contributions entered later. This isn’t motivational math. It’s the same arithmetic as the table above, applied at the individual deposit level. A smaller start that happens now outperforms a larger start that happens in three years, and by more than most people expect.
If the barrier is simply not having opened an account, that’s the only thing to fix this week. A Roth IRA takes about 15 minutes to open at Fidelity, Schwab, or Vanguard — all three offer no-minimum index funds that can be purchased with the first contribution. Set a recurring monthly transfer. Start at whatever you can actually sustain. Adjust upward as income grows. The compounding clock starts the day the first contribution hits the account, not the day you decide to get serious about it.
The Bottom Line
Waiting five years to start investing $400 a month costs roughly $307,000 in final portfolio value by retirement — $283,000 of which comes from lost compounding, not from contributions skipped. To fully recover from that delay, a 33-year-old needs to increase contributions to around $585 a month permanently. A 43-year-old faces a steeper gap that requires higher contributions, later retirement, or adjusted income expectations — ideally a combination of all three.
The number that matters most isn’t how much you’re behind. It’s how much you’d need to invest per month, starting today, to reach a specific retirement income target. That’s a calculation any financial calculator can run in two minutes, and it turns an abstract shortfall into an actionable number. Open the Roth IRA this week. Increase the 401k contribution rate by 2%. Small moves made now have 30-plus years to matter.
For the mental side of why people delay even when they understand the math, The Psychology of Money by Morgan Housel is the clearest and most readable explanation available. For a practical step-by-step system built specifically for people in their 20s and 30s — opening accounts, automating contributions, getting the sequencing right — I Will Teach You to Be Rich by Ramit Sethi covers the exact moves in plain language. And for the investment strategy inside those accounts, The Little Book of Common Sense Investing by John Bogle makes the case for low-cost index funds in a way that doesn’t require a finance background to follow.