How Long Does It Take to Get $1 Million in a 401(k)?
The answer depends on four numbers: what you already have, how much goes in each year (your deferrals plus the employer match), how fast your salary grows, and the return your investments earn. The calculator above simulates this month by month. Below are worked examples, all computed with the same method (monthly compounding, contributions added monthly, salary raises once a year).
Worked Example: $60,000 Salary, Starting at 30
- Contribute 8% = $4,800 in year one
- Employer matches 50% on the first 6% = $1,800 in year one
- Salary rises 3% a year; investments return 8% a year
Results:
- Age 40 (10 years): about $113,000
- Age 50 (20 years): about $403,000
- Age 59 (29 years): $1,000,000
- Total contributions over that time: about $217,000 from you and $81,000 from the employer — roughly 70% of the final balance is investment growth.
Raising the contribution rate is the most powerful lever you control. At 15% instead of 8% (same match), the same saver reaches $1 million around age 54.
How Much Do You Need in Your 401(k) at Each Age?
This table shows the balance you would need today to reach $1 million by age 65 with no further contributions, assuming 8% or 6% annual returns. If your balance is above these numbers, growth alone can get you there; if not, contributions have to make up the gap.
| Age today | Needed at 8% return | Needed at 6% return |
|---|---|---|
| 25 | $41,197 | $91,262 |
| 30 | $61,378 | $123,099 |
| 35 | $91,443 | $166,042 |
| 40 | $136,237 | $223,966 |
| 45 | $202,971 | $302,096 |
| 50 | $302,396 | $407,482 |
| 55 | $450,523 | $549,633 |
Starting from zero, saving $500 a month (you plus employer) at 8% takes about 33 years to reach $1 million; $1,000 a month takes about 25½ years; $2,000 a month takes about 18 years.
The 401(k) Advantages
1. Tax-advantaged growth. In a Traditional 401(k), contributions reduce your taxable income now and growth is not taxed until you withdraw. In a Roth 401(k), contributions are after-tax but qualified withdrawals are tax-free. Either way you avoid yearly taxes on dividends and gains. Note that Traditional 401(k) withdrawals are taxed as ordinary income, so part of a $1 million Traditional balance effectively belongs to the IRS.
2. The employer match. If your employer matches 50% on the first 6% and you contribute 6% of a $75,000 salary, you put in $4,500 and receive $2,250 more — an immediate 50% return on that slice of savings. Matches may be subject to a vesting schedule, so check your plan documents.
3. Higher contribution limits. For 2026 the IRS allows employee deferrals of $24,500, plus an $8,000 catch-up at age 50+ (or $11,250 at ages 60–63 under SECURE 2.0). The IRA limit is $7,500 (+$1,100 catch-up at 50+). Source: IRS, November 2025.
4. Automatic saving. Contributions come out of each paycheck before you see them, which makes consistent saving much easier.
Common Employer Match Formulas
| Match Formula | What It Means | Example ($75K salary, you contribute enough for the full match) |
|---|---|---|
| 100% on first 3% | Dollar-for-dollar up to 3% of salary | You: $2,250 → Employer: $2,250 |
| 100% on first 5% | Dollar-for-dollar up to 5% of salary | You: $3,750 → Employer: $3,750 |
| 50% on first 6% | 50¢ per dollar up to 6% of salary | You: $4,500 → Employer: $2,250 |
| 50% on first 8% | 50¢ per dollar up to 8% of salary | You: $6,000 → Employer: $3,000 |
Rule of thumb: contribute at least enough to collect the full match before directing savings elsewhere.
Maxing Out vs. Partial Contributions
Same 8% return, 30 years, contributions held flat (no raises, no match):
- $24,500/year (the 2026 maximum): about $3.0 million
- $12,000/year: about $1.5 million
- $6,000/year: about $745,000
Because growth is proportional to what goes in, doubling contributions roughly doubles the ending balance.
Traditional vs. Roth 401(k)
Traditional: pre-tax contributions, taxable withdrawals. Roth: after-tax contributions, tax-free qualified withdrawals. A Traditional account tends to win if your tax rate in retirement will be lower than today; a Roth tends to win if it will be the same or higher. Many people split contributions to diversify their future tax exposure. Since 2024, Roth 401(k) balances are no longer subject to required minimum distributions during the owner's lifetime (SECURE 2.0).
Costly 401(k) Mistakes
- Missing the full match: if your employer matches 100% up to 4% and you contribute 2% of a $70,000 salary, you forgo $1,400 a year. Invested for 30 years at 8%, that is about $174,000.
- Cashing out when changing jobs: withdrawals before 59½ are generally taxable plus a 10% additional tax. A $30,000 balance left invested for 25 years at 8% would grow to about $205,000–$220,000 (depending on compounding assumptions).
- Very conservative allocation for decades: $500 a month for 30 years becomes about $416,000 at 5% versus about $915,000 at 9%. Higher-return assets also carry more risk, so match your allocation to your time horizon.
- High fees: a 1% annual fee on a $500,000 balance costs $5,000 a year; index funds often charge under 0.1%.
- Stopping contributions in a downturn: continuing to buy during declines lowers your average purchase price.
When Can You Access Your 401(k)?
- Before 59½: withdrawals are usually taxable and subject to a 10% additional tax, with exceptions such as separation from service in or after the year you turn 55 (the "rule of 55"), disability, and substantially equal periodic payments. (The $10,000 first-time homebuyer exception applies to IRAs, not 401(k)s.)
- 59½ and older: no additional tax; Traditional withdrawals are taxed as income, qualified Roth withdrawals are tax-free.
- Age 73 (75 for people born in 1960 or later): required minimum distributions begin from Traditional balances.
Living Off a $1 Million 401(k)
The "4% rule" comes from William Bengen's 1994 study and the later Trinity study: historically, withdrawing 4% of the starting balance and adjusting for inflation lasted at least 30 years in most US market periods. It is a planning guideline, not a guarantee.
- 4% of $1,000,000 = $40,000/year (about $3,333/month, before taxes)
- The average Social Security retirement benefit is about $2,071/month in 2026 (SSA estimate after the 2.8% COLA)
- Together: roughly $5,400/month before taxes
Remember that $1 million in 25–30 years will buy less than $1 million today: at 3% inflation it has the purchasing power of about $410,000–$480,000 in today's dollars. To plan in today's dollars, lower the return in the calculator by your expected inflation rate.