What is a 401(k) Calculator?
A 401(k) calculator is a financial tool designed to project the future value of your retirement savings based on your current balance, annual contributions, employer matching, and expected investment returns. By factoring in compound interest and tax-advantaged growth, it helps you determine if you are on track to meet your retirement goals.
For the 2026 tax year, our calculator accounts for the latest IRS contribution limits, allowing you to model various scenarios including aggressive saving strategies and different market performance expectations.
How to Maximize Your 401(k) Growth
To get the most out of your employer-sponsored plan, follow these strategic steps:
- 1Secure the Full Employer MatchNever contribute less than the amount required to get your full company match. It is the only "guaranteed" 100% return in the financial world.
- 2Increase Contributions with RaisesEvery time you receive a salary increase, allocate a portion of that raise to your 401(k) before you become accustomed to the higher take-home pay.
- 3Understand the Power of TimeCompound interest works best over long horizons. A $500 monthly contribution started at age 25 grows significantly more than a $1,000 contribution started at age 35.
- 4Factor in 2026 IRS LimitsFor 2026, you can contribute up to $23,500 individually. If you are 50 or older, take advantage of the $7,500 catch-up contribution.
Frequently Asked Questions
How much should I contribute to my 401(k)?
At a minimum, you should contribute enough to receive your full employer match—this is essentially a 100% return on your investment. Financial experts typically recommend saving 15% of your gross income for retirement, which can include both your 401(k) and other accounts like IRAs.
What are the 401(k) contribution limits for 2026?
For 2026, the individual 401(k) contribution limit is $24,500. Employees aged 50 and older can make an additional catch-up contribution of $8,000, for a total of $32,500. These limits apply to elective deferrals across all 401(k) and 403(b) plans.
How does an employer match work?
An employer match is when your company contributes to your 401(k) based on your own contributions. A common formula is a 50% match on the first 6% of your salary. If you earn $100,000 and contribute $6,000, your employer would add $3,000 to your account.
By Frank Sterling (pen name of LifeCalc’s founder; not a licensed financial advisor). Figures on this page were computed with the same code the calculator runs. Data verified 2026-09-01.
How this 401(k) calculator works
The projection runs year by year from your current age to your retirement age. Each year it takes your salary times your contribution percentage, caps it at the IRS elective deferral limit ($24,500 for 2026, or $32,500 from age 50 with the $8,000 catch-up), and calculates the employer match as min(your contribution, salary × match limit %) × match rate. Both amounts are split into twelve monthly deposits. The balance then compounds monthly: balance = balance × (1 + annual return ÷ 12) + monthly employee + monthly employer. Deposits land at the end of each month.
Because the annual return is divided by 12 and compounded monthly, a 7% input behaves like an effective 7.23% a year. The “estimated tax savings” figure is simply your total employee contributions times a flat 22% marginal rate. It is a rough illustration for a traditional (pre-tax) 401(k), not a tax calculation, and it does not apply to Roth contributions.
Assumptions and defaults
- Defaults: age 30, retiring at 65, $25,000 current balance, $85,000 salary, 10% contribution, 50% employer match on the first 6% of salary, 7% annual return.
- Salary stays flat. There are no raises, so contributions and match do not grow with your pay unless you change the inputs.
- The 2026 limits are applied to every future year without indexing, and the catch-up applies once you reach 50. The higher catch-up for ages 60 to 63 under SECURE 2.0 ($11,250 per the IRS) is not modeled.
- Results are in future (nominal) dollars. Inflation is not deducted, so the final balance buys less than the same number today.
- Not modeled: vesting schedules, fees and expense ratios, market volatility, the overall annual limit that includes employer money, taxes on withdrawals, and required minimum distributions.
Worked example: the defaults
At 10% of $85,000 you contribute $8,500 a year. The match applies to the first 6% of salary ($5,100), and 50% of that is $2,550, so your employer adds $2,550 a year. Over 35 years at 7%:
| Your contributions (35 years) | $297,500 |
|---|---|
| Employer match (35 years) | $89,250 |
| Investment growth (on top of the $25,000 start) | $1,534,375 |
| Projected balance | $1,946,125 |
| Estimated tax savings at a flat 22% | $65,450 |
Two sensitivities show where the leverage is. Contribute only 3% and you capture just half the match: $2,550 a year in and $1,275 from the employer grow to about $861,740. Contribute 6% and you take the full $2,550 match, reaching about $1,435,826. The match is the biggest single lever. On returns, the same plan at 5% ends near $1,189,495 and at 9% near $3,285,478, which is why a return assumption deserves as much scrutiny as the contribution rate. Finally, the $1.95 million is nominal: at an assumed 2.5% annual inflation it would be worth roughly $820,000 in today’s dollars.
Limitations: when to talk to a professional
Markets do not return a smooth 7% every year, and the order of returns matters, especially close to retirement. Your plan’s actual match formula may differ from the single tier modeled here (some have tiers, true-ups or vesting periods), so confirm it in your summary plan description. Whether to choose traditional or Roth contributions depends on your current versus expected future tax rate, which this tool does not compare. A fee-only fiduciary financial planner or a CPA can help with Roth conversions, high income phase-outs, rolling over old accounts and withdrawal sequencing.
Related guides
2026 401(k) Limits
Individual Limit
$23,500
Catch-up (Age 50+)
$7,500
Total Limit
$70,000 (Inc. Match)