401(k) Retirement Calculator
See how today’s contributions, your employer’s match, and time compound into a retirement balance.
How your balance grows
Balance by decade
| Age | Balance | Contributed | Employer match | Growth |
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This calculator gives an estimate only, using level assumptions for return and contribution rate. It does not account for taxes on withdrawal, contribution limits set by the IRS, vesting schedules, or fees — actual results will differ. It is not financial, tax, or investment advice.
401(k) Calculator: Find Out What Your Retirement Savings Could Really Be Worth
Most people know they should be saving in a 401(k). Far fewer know what their current contribution rate actually adds up to by retirement. A 401(k) calculator closes that gap — it turns a vague plan (“I put in a little every paycheck”) into a real number you can plan around.
Use the calculator above to model your own numbers. This guide explains what each input means, why employer matching matters more than most people realize, and how small changes today change your outcome decades from now.
What a 401(k) calculator actually does
A 401(k) is a workplace retirement account. Each pay period, a percentage of your salary is deducted and invested, usually before tax. Many employers add a match on top — essentially free money added to your account based on how much you personally contribute.
A 401(k) calculator projects your account balance at retirement by combining:
- Your current balance — what’s already in the account today
- Your contribution rate — the percentage of salary you personally set aside
- Employer match — the percentage your employer adds, often up to a cap
- Expected annual return — the average growth rate of your investments over time
- Salary growth — since contributions are usually a percentage of pay, a raise means a bigger contribution
- Time horizon — how many years are left until you plan to retire
The calculator then compounds all of this month by month, so you can see not just a final number, but how much of it came from your own contributions, how much came from your employer, and how much came purely from investment growth.
Why the employer match is the number to pay attention to
If your employer matches 50% of what you contribute, up to 6% of your salary, and you only contribute 3%, you’re leaving unmatched money on the table every single paycheck. That match doesn’t show up as a bonus or a line on your salary — it just quietly disappears.
Contributing at least enough to capture the full match is usually the highest-return decision available in a retirement plan, because it’s an immediate, guaranteed return before the money is even invested. The calculator above separates “your contributions,” “employer match,” and “investment growth” into three different figures specifically so this becomes visible instead of buried inside one lump balance.
Why time matters more than the contribution amount
Two people can contribute the exact same amount over their careers and end up with very different balances, purely because of when they started. Money invested in your 20s and 30s has decades to compound, and compounding accelerates the longer it runs — most of the growth in a long-term 401(k) balance happens in the final stretch before retirement, built on gains from money that was invested early.
This is why the calculator weights the “years until retirement” input so heavily. Delaying contributions by even five years, especially early in a career, can reduce a final balance far more than it seems like it should, because those are the five years the balance would have had the longest to grow.
How to use the inputs realistically
Expected annual return: A common long-term assumption for a diversified stock-heavy portfolio is in the 6–8% range, though returns in any single year can vary widely and aren’t guaranteed. A more conservative assumption is reasonable if your portfolio leans toward bonds or cash.
Salary growth: Even a modest 2–3% annual increase compounds meaningfully over a 30-year career, since your contribution amount grows along with your pay.
Contribution rate: Many financial guidelines suggest aiming for 10–15% of salary total (including employer match) over a career, though the right number depends on your income, expenses, and other savings goals.
Match cap: Check your plan documents for the exact match formula — it’s often written as something like “50% of the first 6% you contribute,” which is exactly what the match rate and match cap fields are built to model.
What this calculator doesn’t account for
To keep the numbers easy to understand, this tool uses simplified, level assumptions. It does not factor in:
- IRS contribution limits, which are set annually and cap how much you and your employer can contribute combined
- Taxes on withdrawal — traditional 401(k) withdrawals in retirement are typically taxed as income
- Vesting schedules, which can delay when employer match money is fully yours
- Investment fees, which reduce net returns over time
- Market volatility — real returns don’t arrive as a smooth, consistent percentage every year
Because of this, treat the result as a directional estimate rather than a guarantee. It’s a tool for comparing scenarios — “what if I contributed 2% more?” or “what if I retired three years later?” — not a substitute for a full financial plan.
Frequently asked questions
How much should I contribute to my 401(k)?
At minimum, enough to get your full employer match. Beyond that, many planners suggest working toward 10–15% of salary total, adjusted for your own goals, debt, and other savings priorities.
What’s a good rate of return to assume?
A commonly used long-term average for a diversified stock portfolio is around 7% after inflation, though this varies by asset allocation and isn’t guaranteed in any given year.
Does employer match count toward the contribution limit?
Employer contributions are typically subject to a separate, higher combined limit than the employee-only contribution limit. Check current IRS limits, since they’re adjusted most years.
What happens if I change jobs?
Vested balances are generally yours to keep, roll into a new employer’s plan, or roll into an IRA. Unvested employer contributions may be forfeited, depending on your plan’s vesting schedule.
Is this calculator financial advice?
No. It’s an educational estimation tool. For decisions specific to your situation, a licensed financial advisor can account for taxes, other accounts, and your full financial picture.