April 23, 2026 · 11 min read
Your 401(k) is likely your single most powerful retirement savings vehicle — and yet most people have no idea what their account will actually be worth when they retire. Our free 401(k) calculator shows you exactly what to expect, year by year, so you can make confident decisions today. This guide explains every field, every number, and every strategy you need to know.
A 401(k) is an employer-sponsored retirement savings account that lets you set aside a portion of each paycheck before taxes are taken out. Your investments grow tax-deferred — meaning you don't pay income tax on the gains until you withdraw the money in retirement. Many employers also contribute free matching funds up to a certain percentage, which is essentially additional compensation you would leave on the table if you don't participate.
The power of a 401(k) comes from three forces working together: your regular contributions, your employer's free matching money, and the compound investment growth that compounds both of those over decades. Our calculator models all three simultaneously so you can see your true projected retirement balance.
Key benefit: For 2025, you can contribute up to $23,500 per year to a 401(k) if you are under 50, or $31,000 per year if you are 50 or older (the extra is called a "catch-up contribution"). These limits are adjusted annually by the IRS.
Current Age
How old you are right now. The calculator uses this to determine how many years your money has to grow before you retire. Every additional year of growth makes a significant difference due to compound interest.
Retirement Age
The age at which you plan to stop working and start drawing from your retirement accounts. The default is 65, which aligns with traditional full Social Security benefits, but you can adjust this to model early retirement or working longer.
Annual Salary
Your current gross (pre-tax) annual salary. This is used to calculate both your contribution amount and the employer match. As your salary grows with annual raises, your contributions grow proportionally too.
Current 401(k) Balance
How much you already have saved in your 401(k) today. If you are just starting out, enter 0. If you have been contributing for years, check your latest account statement for the current balance.
Your Contribution (%)
The percentage of your salary you contribute each paycheck. Most financial advisors recommend contributing at least enough to get the full employer match. A common starting point is 6%, and aiming for 10–15% is ideal for long-term retirement security.
Employer Match (%)
The percentage of your salary your employer contributes as matching funds. A common structure is "100% match up to 3% of salary" or "50% match up to 6%." Enter the effective employer contribution percentage here. If your employer doesn't offer a match, enter 0.
Annual Return (%)
The average annual investment return you expect from your 401(k) investments. The historical average for a diversified stock portfolio is roughly 7–10% before inflation. The calculator defaults to 7%, which is a widely cited conservative-to-moderate estimate. Use the quick-fill presets (5%, 7%, 9%) for easy scenario comparisons.
Annual Raise (%)
How much your salary grows each year on average. Since your contributions are a percentage of salary, raises mean larger contributions over time. The default 2% approximates inflation-adjusted wage growth. If you expect faster career progression, try 3–4%.
Start by typing your current age and the age you plan to retire. The number of years between them is your savings runway. For example, if you are 32 and plan to retire at 65, you have 33 years of compounding working in your favor.
Type your annual gross salary — the number on your offer letter or W-2 before any deductions. Then enter your current 401(k) balance. If you are brand new to saving, enter 0 in the balance field.
Enter the percentage of your salary you contribute (e.g. 6%) and your employer's match percentage (e.g. 3%). Together these determine your total annual investment. Check your HR portal or benefits documentation if you are unsure of your match rate.
Use the quick-fill presets to model different market scenarios: Conservative (5%), Moderate (7%), or Aggressive (9%). You can also type any custom value. Running all three gives you a realistic range — your actual balance will likely fall somewhere in the middle.
Enter how much your salary is likely to grow each year. If your company gives annual merit raises of about 2–3%, use that figure. If you're in a fast-growing career, you might use 4–5%. This compounds your contributions over time.
Hit the indigo calculate button. Your results appear instantly, showing your projected retirement balance, a breakdown of where the money came from, and a year-by-year growth timeline.
After calculating, you'll see several components in the results panel:
Projected Balance at Retirement
The large number at the top — this is your estimated total 401(k) balance when you reach your target retirement age. It combines your starting balance, all future contributions, employer match, and compound investment growth.
Your Contributions
The total amount you personally contributed from your paychecks over the entire savings period. This is money that came directly out of your salary.
Employer Match
Free money your employer added on top of your contributions. This is one of the biggest financial benefits of a 401(k) — always contribute at least enough to get the full match.
Investment Growth
The profit generated by your investments — dividends, interest, and capital appreciation compounding over the years. For long time horizons, this number often exceeds the total contributions, which illustrates the enormous power of compound interest.
Growth Timeline
A visual bar chart showing your projected balance at evenly spaced intervals across your savings journey. This helps you track whether you are on pace and understand when growth really starts to accelerate (typically in the final third of your savings period).
$55,000 salary · 6% contribution · 3% employer match · 7% return · retiring at 65
40 years of compounding turns $316K of invested money into over $1.3M.
$95,000 salary · 10% contribution · 4% employer match · 7% return · $50,000 existing balance · retiring at 65
Higher salary and contribution rate compensate for starting later.
$80,000 salary · 15% contribution · 4% employer match · 7% return · current age 30
Aggressive saving (15%) makes early retirement at 55 viable.
Always Get the Full Employer Match
If your employer matches up to 3% of your salary and you only contribute 2%, you are leaving free money on the table. This is the single highest-return "investment" available — it's an instant 50–100% return on your contribution.
Increase Your Contribution Rate Gradually
Can't afford to contribute 10% right now? Start at 3–4% and increase by 1% every time you get a raise. You'll barely notice the difference in take-home pay because the raise offsets the increase.
Don't Cash Out When Changing Jobs
When you leave a job, roll your 401(k) into your new employer's plan or a rollover IRA. Cashing out triggers income taxes plus a 10% early withdrawal penalty — and destroys years of compound growth.
Diversify Your Investments
Most 401(k) plans offer a range of mutual funds and index funds. A diversified portfolio (broad stock index funds + some bonds) typically outperforms picking individual stocks and reduces volatility. Target-date funds are an easy "set it and forget it" option.
Use the Scenario Presets to Plan
Run the calculator three times — once with 5%, once with 7%, and once with 9% annual return. The range between those projections gives you a realistic best-case and worst-case picture so you can plan conservatively.
What's the difference between a Traditional 401(k) and a Roth 401(k)?
Traditional 401(k): contributions are pre-tax (reduces your taxable income now), but withdrawals in retirement are taxed as ordinary income. Roth 401(k): contributions are after-tax (no immediate tax break), but all growth and withdrawals in retirement are completely tax-free. If you expect to be in a higher tax bracket in retirement, Roth is often better.
Does the calculator account for inflation?
Not directly. The projected balance is in today's dollars only if your "annual return" is an inflation-adjusted (real) rate. If you use the nominal historical return (7–10%), the purchasing power of your future balance will be lower than the number shown. To account for inflation, subtract ~2.5–3% from your return rate (e.g., use 4–5% instead of 7%).
What happens to my 401(k) if I change jobs?
Your vested balance is yours to keep. You can leave it with your former employer's plan, roll it into your new employer's plan, roll it into an IRA, or (not recommended) cash it out and pay taxes and penalties.
Can I contribute to both a 401(k) and an IRA?
Yes. Contributing to a 401(k) does not prevent you from contributing to a Traditional or Roth IRA. However, your ability to deduct Traditional IRA contributions may be limited if you (or your spouse) have a workplace retirement plan. Roth IRA contributions are subject to income limits.
Why is investment growth sometimes bigger than contributions?
This is the magic of compound interest. Over long periods (20+ years), the returns on your returns start to dwarf the original contributions. A dollar invested at 30 has 35 years to double roughly 3–4 times before you turn 65. This is why starting early — even with small amounts — is so impactful.
| Item | Amount |
|---|---|
| Employee contribution limit (under 50) | $23,500/year |
| Catch-up contribution (age 50+) | +$7,500/year ($31,000 total) |
| Super catch-up (age 60–63) | +$11,250/year ($34,750 total) |
| Total limit (employee + employer) | $70,000/year |
| Early withdrawal penalty (before 59½) | 10% + income tax |
| Required Minimum Distributions (RMDs) begin | Age 73 |
Use our free 401(k) calculator to see how your savings, employer match, and compound growth add up over time.
Disclaimer: All projections are estimates for educational purposes only. Past investment returns do not guarantee future results. Consult a qualified financial advisor for personalized retirement planning advice.
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Henry
Founder & Developer, Online Calculator Suite
Henry is the independent creator of Online Calculator Suite, based in Utah. He builds and maintains every calculator on this site and writes the guides, checking formulas against published sources such as the IRS, CDC and NIH. He is not a licensed financial advisor or medical professional, so results are for information only.