How to Use the 401(k) Retirement Calculator
This 401(k) Retirement Calculator helps you project the growth of your retirement savings. Enter your current balance, annual salary, your contribution percentage, employer match, and expected annual return to see your projected balance at retirement.
The calculator shows your projected 401(k) balance, your total contributions, employer match total, investment growth, and estimated monthly retirement income using the 4% withdrawal rule. It also includes an age-based growth timeline so you can track your progress year by year.
Pro tip: Try increasing your contribution by just 1-2% to see how it compounds over decades. Even small increases today can mean tens of thousands more at retirement.
401(k) Formula & Methodology
Future Value = P × (1 + r)^n + PMT × [((1 + r)^n − 1) / r]
Where:
- P = Current 401(k) balance
- PMT = Total monthly contribution (your contribution + employer match)
- r = Monthly return rate (annual return ÷ 12)
- n = Total months until retirement
Example — Maxing Your 401(k) Over 30 Years
Scenario: Sarah, age 35, earns $75,000/year and contributes 15% ($11,250/year). Her employer matches 100% of the first 4% ($3,000/year). She has $25,000 saved already and expects 7% annual returns.
- Annual Contribution: $75,000 × 15% = $11,250
- Employer Match: $75,000 × 4% = $3,000
- Total Annual: $11,250 + $3,000 = $14,250
- Monthly Contribution: $14,250 ÷ 12 = $1,187.50
After 30 years (age 65):
- Growth Factor at 7%: (1 + 0.07/12)^360 = 8.116
- Future Value of $25,000: $25,000 × 8.116 = $202,900
- Future Value of Contributions: $1,187.50 × [(8.116 − 1) / (0.07/12)] = $1,446,000
- Total Projected Balance: ~$1,649,000
- Her Contributions: $25,000 + ($11,250 × 30) = $362,500
- Employer Contributions: $3,000 × 30 = $90,000
- Investment Growth: $1,649,000 − $452,500 = $1,196,500
- Estimated Monthly Income (4% rule): ~$5,497
2026 401(k) Contribution Limits
| Limit Type | 2026 Amount |
|---|---|
| Employee Elective Deferral (under 50) | $23,500 |
| Catch-Up Contribution (age 50+) | $7,500 |
| Super Catch-Up (ages 60-63, SECURE 2.0) | $11,250 |
| Total Employer + Employee Limit | $70,000 |
* Based on IRS guidelines for 2026. SECURE 2.0 increased catch-up for ages 60-63.
Why Your 401(k) is the Most Powerful Retirement Tool
A 401(k) offers three massive advantages over regular taxable accounts:
- Tax-deferred growth: Your contributions reduce your taxable income today, and your money grows tax-free until withdrawal. In 2026, contributing $23,500 saves you approximately $5,875 in federal taxes if you are in the 25% bracket.
- Employer match = free money: If your employer offers a 4% match, that is a guaranteed 100% return on the first 4% you contribute. Not contributing enough to get the full match is literally leaving free money on the table.
- High contribution limits: At $23,500 (2026), the 401(k) allows far more tax-advantaged saving than an IRA ($7,000). Combined with employer match, you can put away $70,000/year total.
401(k) Investment Strategies
Target-Date Funds
The most popular 401(k) investment. A 2055 target-date fund automatically shifts from stocks to bonds as you approach retirement. They are a great default choice for hands-off investors.
Index Fund Portfolio
For lower fees and more control, build a simple portfolio: 80-90% S&P 500 index fund and 10-20% bond index fund. Rebalance annually. This approach has historically returned 7-10% annually with minimal fees.
Roth 401(k) Option
Many employers now offer a Roth 401(k) option. You contribute after-tax dollars, but qualified withdrawals in retirement are tax-free. This is powerful if you expect to be in a higher tax bracket in retirement.
How Employer Matching Works
Common employer match structures include:
- 100% match on first 4%: You contribute 4%, employer adds 4%. Instant 100% return.
- 50% match on first 6%: You contribute 6%, employer adds 3%. Still a great 50% return.
- Safe harbor match: Employer must contribute 3% of salary regardless, or 100% on first 3% plus 50% on next 2%.
- Profit-sharing: Employer contributes a percentage of profits — varies year to year.
Always contribute at least enough to get the full employer match. It is the closest thing to free money in personal finance.
Data Sources & Methodology
Methodology: Future value is calculated using the standard compound interest formula with monthly compounding. Estimated retirement income uses the 4% safe withdrawal rule (Bengen, 1994). Past performance does not guarantee future results.
Frequently Asked Questions
How much should I contribute to my 401(k)?
At minimum, contribute enough to get the full employer match (typically 4-6% of salary). The ideal target is 15% of your gross income including employer match. In 2026, the maximum employee contribution is $23,500 ($31,000 if age 60-63). A common strategy: contribute 10-15% consistently throughout your career.
Should I choose traditional or Roth 401(k)?
A Traditional 401(k) saves you taxes now (contributions are pre-tax), which is ideal if you are in a high tax bracket today. A Roth 401(k) saves you taxes later (withdrawals are tax-free), which is ideal if you expect higher income in retirement. Many financial advisors recommend having some of both for tax diversification.
What happens to my 401(k) when I change jobs?
You have four options: (1) Leave it in your former employer's plan, (2) Roll it into your new employer's 401(k), (3) Roll it into a Traditional IRA (more investment choices), or (4) Cash out (not recommended — you will pay income tax plus a 10% penalty). Rolling over to an IRA or new 401(k) is typically the best choice.
Can I withdraw from my 401(k) early?
Early withdrawals before age 59½ are subject to a 10% penalty plus ordinary income tax. Exceptions include: financial hardship, first-time home purchase ($10,000 limit), disability, medical expenses exceeding 7.5% of AGI, and substantially equal periodic payments (72t). Loans from your 401(k) (up to $50,000 or 50% of vested balance) are allowed by most plans without penalty.
What is the 4% rule?
The 4% rule, developed by financial advisor Bill Bengen in 1994, suggests that retirees can withdraw 4% of their portfolio in the first year of retirement, then adjust that amount for inflation each year, with a high probability of their savings lasting 30+ years. For a $1 million portfolio, that means withdrawing $40,000 in the first year ($3,333/month).
Related Tools
- Roth IRA Growth Calculator — Compare Roth IRA growth vs 401(k).
- Roth vs Traditional IRA Calculator — Choose the right IRA type.
- Solo 401k Contribution Calculator — For self-employed professionals.
- Retirement Savings Calculator — Full retirement planning with the 4% rule.
📖 Related Reading
For a complete guide to maximizing your 401(k), read our blog post: 401(k) Retirement Calculator Guide 2026.