401k Calculator

A 401(k) calculator estimates how your current 401(k) balance and future contributions could grow by the time you retire. Instead of guessing at a round number, this tool models your specific inputs — current balance, salary, contribution rate, employer match, expected investment return, salary growth, and inflation — to project a realistic future balance, broken down into what came from you, what came from your employer, and what came from investment growth.

This calculator is built for anyone contributing to a workplace 401(k) who wants a clearer picture of where they’re headed: someone just starting their career and deciding what contribution rate to pick, a mid-career saver wondering whether to increase contributions, or someone closer to retirement checking whether catch-up contributions make sense. Understanding your projected balance matters because 401(k) growth isn’t linear — employer matching, compounding, and time interact in ways that are easy to underestimate. Estimating your numbers now, before you lock in a contribution rate for the year, helps you see the real cost of under-contributing and the real payoff of contributing even a little more.

Use the 401(k) Calculator ↑

What Is a 401(k) Calculator?

In simple terms, a 401(k) retirement calculator is a tool that projects how your workplace retirement account could grow over time by combining four things: the money already in your account, the money you’ll add through payroll contributions, the money your employer adds through matching, and the investment growth on all of it, compounded over your remaining working years.

Unlike a basic compound interest calculator, a proper 401k growth calculator has to account for contributions that happen periodically (not as one lump sum), a salary that typically rises each year, an employer match that’s usually capped rather than unlimited, and the fact that a dollar at retirement buys less than a dollar today. This tool is designed to handle all of that together rather than treating each piece in isolation.

Whether you search for it as a 401k calculator, a 401k retirement calculator, a 401k contribution calculator, or a 401k savings calculator, you’re looking for the same core function: a retirement calculator 401k savers can trust to model contributions, employer matching, and compounding together. Some people specifically want a 401k calculator by age to see how their numbers compare at different life stages, while others are looking for a 401k compound interest calculator or a straightforward answer to “how much will my 401k be worth” by retirement. This page works as a 401k calculator with employer match (also described as a 401k calculator with employer contribution), a 401k future value calculator, and a full 401k retirement savings calculator — all in one tool.

How to Use the 401(k) Calculator

How Does a 401(k) Grow?

A 401(k) balance grows from five interacting sources, and understanding each one separately makes the total much less mysterious:

• Contributions: The money you elect to contribute from each paycheck, usually a percentage of salary
• Employer matching: Additional money your employer adds based on your contributions, typically up to a capped percentage of salary
• Compound growth: Investment returns earned not just on your original contributions, but on all prior growth too
• Salary increases: As your pay rises, contributions calculated as a percentage of salary rise with it, even at a fixed contribution rate
• Time: The single biggest lever — more years means more compounding cycles, which is why starting early matters more than almost any other factor

How Does Employer 401(k) Matching Work?

Employer matching is usually described as a percentage match up to a cap — for example, “your employer matches 50% of your contributions, up to 6% of your salary.” Here’s exactly how that works out in dollars for a $75,000 salary:

The important detail: the employer match applies only up to the stated limit. If you contribute more than 6% of salary in this example, the extra amount above 6% still grows in your account, but it isn’t matched — the employer’s contribution stays capped at $2,250. This calculator applies that same capping logic automatically, so raising your contribution rate above the match limit boosts your own balance without inflating the employer match beyond what your plan actually offers.

How Much Should I Contribute to My 401(k)?

There’s no single right contribution percentage for everyone, but a few general considerations come up repeatedly in retirement planning:

This is general education, not personalized financial advice — your right contribution rate depends on your full financial picture, and a financial advisor or tax professional can help you weigh trade-offs specific to your situation.

How Much Will My 401(k) Be Worth at Retirement?

The honest answer is: it depends on your starting balance, contributions, employer match, investment return, time horizon, salary growth, fees, and inflation — which is exactly why this calculator asks for each of those inputs individually rather than giving you one generic number. Here’s what that looks like using the calculator’s own suggested defaults, so you can see the full breakdown in action.

In this example, roughly 75% of the final balance comes from investment growth, not contributions — a reminder of how much compounding does the heavy lifting over a 35-year career. Your projected balance at age 65 could be $1.73 million in nominal dollars, equivalent to approximately $614,000 in today’s purchasing power after adjusting for 3% average annual inflation.

Year-by-Year Projection (Sample)

The interactive calculator above generates a full year-by-year table for your exact inputs, with an option to expand the complete timeline. Here’s a preview using the default example (age, salary, and balance shown at each year-end):

Note how contribution dollar amounts rise each year even though the contribution percentage stays fixed at 6% — that’s the salary growth assumption at work, not a change in contribution rate.

Scenario Analysis: Conservative, Expected, and Optimistic Returns

Investment returns aren’t constant year to year, so it helps to see a range rather than a single number. These are hypothetical scenarios, not predictions, using the same contribution assumptions as the example above:

The Effect of Increasing Your Contribution Rate

Small contribution increases compound into large differences over a career. Here’s what raising the contribution rate from 6% to 10% does to the same example (all other assumptions unchanged):

In this scenario, contributing an additional $250 a month over 35 years corresponds to roughly $640,000 more at retirement — a useful illustration of why even modest contribution increases are worth considering, though your own results will vary with your actual timeline and return assumptions.

What Is the Maximum 401(k) Contribution?

IRS 401(k) contribution limits change from year to year, so treat any specific number as tied to a specific tax year rather than a permanent fact. For tax year 2026, the IRS has set the following limits:

Source: IRS.gov, “401(k) limit increases to $24,500 for 2026, IRA limit increases to $7,500.” Always confirm current-year limits directly with the IRS or your plan administrator, since these figures are adjusted annually and can change.

If you’re 50 or older, this calculator lets you enable catch-up contributions, which apply the regular limit plus the applicable catch-up amount for your age band. Not everyone is eligible for every catch-up tier — the standard age-50 catch-up applies broadly, while the higher “super catch-up” for ages 60-63 is a newer provision under SECURE 2.0, so confirm your plan’s specific rules before assuming eligibility.

How Does Compound Interest Affect a 401(k)?

Compound growth means your investment returns earn their own returns over time, which is why starting early has an outsized effect compared to contributing more later. Consider this simplified, illustrative example: someone who contributes $6,000 a year starting at age 25 and stops after just 10 years (never contributing again) versus someone who waits until age 35 to start, also contributing $6,000 a year for 10 years and then stopping. Both let the balance grow untouched at 7% until age 65.

Both savers contributed the exact same total amount, $60,000, but the early starter’s balance ends up roughly double the late starter’s, purely because those dollars had 10 extra years to compound. This is a simplified, illustrative comparison, not a recommendation to stop contributing after 10 years — but it demonstrates why time in the market is such a powerful variable in retirement projections.

Traditional 401(k) vs. Roth 401(k)

The core difference between a traditional and Roth 401(k) is when you pay taxes, not how the investments grow. Neither option is universally better — the right choice depends on your current tax bracket, expected future tax bracket, and personal preferences.

401(k) Withdrawal Rules

At a high level, 401(k) plans are designed for retirement, and withdrawing funds before a certain age typically triggers a penalty in addition to any applicable income tax, with some exceptions. Once you reach the plan’s required distribution age, you’re generally required to begin taking minimum distributions from traditional accounts. Specific ages, penalty percentages, and exceptions are set by tax law and can change, so this page intentionally avoids stating specific dollar thresholds or dates as permanent facts — check current IRS guidance or a tax professional for rules that apply to your situation.

How the Calculation Works

This calculator does not simply multiply an annual contribution by the number of years. Instead, for every period until retirement, it:

Contributions compound individually from the period they’re made, not as a single lump sum at the end — this is why a monthly-contribution projection differs slightly from an annual-lump-sum estimate of the same total dollar amount. Actual results will vary because investment returns are never perfectly constant year over year; this model assumes a steady average return for simplicity, which is a common simplification used across retirement calculators but is not how markets actually behave day to day.

Frequently Asked Questions

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