Formulas and 2026 figures checked & updated: July 2026
How to Use the 401(k) Calculator
- Enter your current annual salary — this determines both your contribution amount and your employer's match cap.
- Set your contribution percentage, the share of each paycheck you want deferred into the 401(k).
- Enter your employer's match formula: the match rate (such as 50% or 100%) and the percentage of salary it applies up to (such as 6%).
- Enter your current age and target retirement age — catch-up contributions apply automatically once you turn 50.
- Enter your current 401(k) balance and your expected annual rate of return (many savers use 6–8% for a diversified stock/bond mix).
- Review your projected balance, contribution breakdown, and growth chart.
- Example: a 35-year-old earning $80,000 with a $50,000 balance, contributing 10% with a 50%-to-6% match, could reach roughly $1.3M by age 65 at a 7% return.
What This Calculator Does
The 401(k) Calculator projects the balance you can build in your employer-sponsored 401(k) by combining your current account balance, ongoing payroll contributions, employer matching dollars, and years of compound investment growth into a single retirement forecast. As a 401(k) contribution calculator, it factors in the 2026 IRS limits automatically, so the projection reflects what you can realistically defer from each paycheck rather than an unrestricted number.
The result is driven by seven inputs: your salary, your contribution percentage, your employer's match formula (both the match rate and the salary cap it applies to), your current age, your planned retirement age, your existing balance, and your expected annual rate of return. Financial planners commonly cite a rule of thumb of saving 10–15% of gross income for retirement, including any employer match, to stay on track for a comparable standard of living in retirement, and the S&P 500's long-run average return has run close to 10% nominal — roughly 7% after inflation — a figure many savers use as a starting point for the return assumption. Contribution rate and years invested tend to matter far more to the final balance than fine-tuning the return assumption, which is why starting early and capturing the full employer match are the two levers with the biggest payoff.
This tool is useful whenever you need to decide how much to defer from your paycheck — for example, when setting up a new job's benefits, deciding whether to raise your contribution percentage during open enrollment, or checking whether you're on pace to max out the annual IRS limit before year-end. It also helps quantify the cost of leaving employer match money unclaimed, compare match formulas between competing job offers, and see how catch-up contributions at age 50+ can accelerate a late start toward retirement.
Formula
FV = PV(1+r)^n + PMT × [((1+r)^n − 1) / r]Your 401(k) balance grows from two combined contribution streams — your own paycheck deferrals plus your employer's matching contributions — both compounding monthly alongside your existing balance.
- PVCurrent 401(k) balance
- PMTCombined monthly contribution (employee + employer match)
- rMonthly rate of return (annual return ÷ 12)
- nTotal number of months until retirement
Examples
Example 1: $90,000 salary, 10% contribution, 100% match up to 3%
Employee contributes $9,000/year (10% of $90,000); employer matches 100% of the first 3% ($2,700/year). Current balance $35,000, age 32 to 65, 7% return.
Projected balance at 65 ≈ $1,680,000, including roughly $89,000 in 'free' employer contributions over the working years.
Example 2: Maxing out the 2026 limit at age 52
A 52-year-old earning $180,000 contributes the full 2026 employee limit of $24,500, plus the $8,000 age-50+ catch-up, with a 50% match up to 6% of salary.
Total annual contribution including match ≈ $36,400. Over 13 years to age 65 at 7% return, the balance grows by roughly $760,000 from this point forward.
Example 3: Leaving match money on the table
A 30-year-old earning $70,000 contributes only 2% ($1,400/year) when the employer matches 100% up to 4% ($2,800/year) — missing $1,400/year in free match.
Bumping the contribution from 2% to 4% costs the employee an extra $1,400/year but adds another $1,400/year in match — over 35 years at 7%, that's roughly $290,000 in lost retirement savings if left unclaimed.
Key Terms Explained
- Employer Match
- Money your employer adds to your 401(k) based on your own contributions — effectively free retirement savings, up to a limit.
- Vesting
- The schedule by which employer contributions become fully yours. Leaving before you're vested can forfeit the unvested portion.
- Compound Interest
- Interest earned on both your original balance and previously earned interest, so growth accelerates the longer money stays invested.
- Roth IRA
- A retirement account funded with after-tax dollars. Contributions and earnings grow tax-free, and qualified withdrawals in retirement owe no tax.
- Traditional IRA
- A retirement account funded with pre-tax (or deductible) dollars. Contributions may lower your taxable income today, but withdrawals in retirement are taxed as ordinary income.
Continue Your Financial Planning
Methodology
This calculator compounds your existing balance plus combined monthly contributions (your deferral plus employer match) using the standard future-value-of-an-annuity formula, applying growth monthly rather than annually for a more precise projection. Contributions are automatically capped at the 2026 IRS limit, with catch-up amounts layered in once you reach age 50.
Frequently Asked Questions
What is the 401(k) contribution limit for 2026?+
Employee limit: $24,500. Catch-up (age 50–59 and 64+): $8,000 extra. Super catch-up (age 60–63): $11,250 extra. Overall defined-contribution limit excluding catch-up: $72,000.
How does employer matching work?+
A 100% match on the first 3% means if you earn $100K and contribute 3% ($3,000), your employer adds $3,000. Always contribute enough to capture the full match — it's a 100% instant return.
How much should I contribute to my 401(k) each year?+
A common rule of thumb is to save 10–15% of your gross income for retirement, including any employer match. At minimum, contribute enough to capture the full employer match since it's an immediate, guaranteed return that a taxable brokerage account can't match. If you're behind on savings, the catch-up contribution available at age 50 lets you set aside significantly more each year.
What happens to my 401(k) when I leave my job?+
You generally have four options: leave the balance in your former employer's plan if allowed, roll it into your new employer's 401(k), roll it into an IRA, or cash it out. Rolling over into an IRA or new 401(k) preserves the tax-deferred status and avoids the 10% early-withdrawal penalty and income taxes that apply to cashing out before age 59½.
Can I contribute to both a 401(k) and an IRA in the same year?+
Yes. 401(k) and IRA contribution limits are separate, so you can max out your workplace 401(k) and still contribute to a Traditional or Roth IRA in the same year, subject to IRA income limits for Roth eligibility and deduction phase-outs for Traditional IRAs. Many savers use the 401(k) for the employer match and higher limit, then add an IRA for additional investment options.
Can I save my results?+
Yes. Use “Save results” to store a snapshot. Without an account it remains in this browser. If you log in, saved scenarios sync securely to your SmartRates account so they are available on your other devices.
How do I share my calculation?+
Click “Share” in the toolbar to copy a link (or open your device’s share sheet). The link encodes your exact inputs, so whoever opens it sees the calculator pre-filled with the same numbers and the same result.
Can I email my calculator results?+
Yes. Click “Email results” to open your default email application with the current inputs, results, and calculator link already included. Review the message and choose the recipient before sending.
Can I export or print my results as a PDF?+
Yes. Click “Export PDF” to open a clean, printable summary of your inputs and results that you can save as a PDF or print. It includes a timestamp and a link back to the calculator.
How accurate are the calculator results?+
The arithmetic follows the formula and assumptions documented on this page. The result is still an estimate because actual rates, fees, taxes, timing conventions, eligibility rules, and provider calculations can differ. Use figures from your official quote, statement, contract, or tax form before making a financial decision.
Which inputs have the biggest effect on the result?+
Rate, time, starting balance, recurring payments or contributions, and fees usually have the largest effects. Change one input at a time to create a conservative, expected, and optimistic scenario instead of relying on a single forecast.
Are taxes, fees, and inflation included?+
Only when they appear as an input or are explicitly described in the methodology. Do not assume an omitted cost is zero. Review the formula and methodology sections to see exactly what is included before comparing the result with an outside quote.
Can this calculator predict future rates or returns?+
No. A calculator projects the assumptions entered; it cannot predict market returns, inflation, variable interest rates, tax-law changes, or provider decisions. Rerun the calculation with several assumptions to understand the range of possible outcomes.
Why might my lender, bank, broker, or tax software show a different result?+
Professional systems may use daily timing, transaction dates, compounding conventions, rounding rules, account-specific fees, credits, eligibility details, or regulations that a general-purpose calculator cannot know. A small difference can be rounding; a large difference usually means an assumption or included cost is different.
Disclaimer: Calculations are for informational purposes only and do not constitute professional financial advice. Please consult with a certified professional before making financial decisions.