Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Balance at retirement
$1,238,631
Your contributions
$259,599
Employer match
$129,800
Investment growth
$801,232
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter current balance ($).
- 2Enter annual salary ($).
- 3Enter your contribution (%).
- 4Enter employer match (% of salary).
- 5Enter years to retirement.
- 6Enter annual return (%).
- 7Enter annual raise (%).
- 8Read your balance at retirement on the right — it updates as you type.
- 9Hit Share to keep the scenario or send it to someone.
About this calculator
An employer match is an instant, guaranteed return on your contribution — usually the highest return available anywhere. This projects your balance with contributions, match, salary growth, and compounding.
Worked example
Using the values the calculator loads with:
Inputs
- Current balance: 48000 $
- Annual salary: 95000 $
- Your contribution: 8 %
- Employer match: 4 % of salary
- Years to retirement: 25
- Annual return: 7 %
- Annual raise: 2.5 %
Results
- Balance at retirement: $1,238,630.95
- Your contributions: $259,599.01
- Employer match: $129,799.50
- Investment growth: $801,232.45
What each field means
Inputs
- Current balance ($)
- The current balance used in the calculation, measured in $. Starts at 48000 $ so you have a working example on load.
- Annual salary ($)
- The annual salary used in the calculation, measured in $. Starts at 95000 $ so you have a working example on load.
- Your contribution (%)
- The your contribution used in the calculation, measured in %. Starts at 8 % so you have a working example on load. Accepted range: 0–60 %.
- Employer match (% of salary)
- The employer match used in the calculation, measured in % of salary. Starts at 4 % of salary so you have a working example on load. Accepted range: 0–20 % of salary.
- Years to retirement
- The years to retirement used in the calculation. Starts at 25 so you have a working example on load.
- Annual return (%)
- The annual return used in the calculation, measured in %. Starts at 7 % so you have a working example on load.
- Annual raise (%)
- The annual raise used in the calculation, measured in %. Starts at 2.5 % so you have a working example on load.
Results
- Balance at retirement
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Your contributions
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Employer match
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Investment growth
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the 401(k) calculator work?
An employer match is an instant, guaranteed return on your contribution — usually the highest return available anywhere. This projects your balance with contributions, match, salary growth, and compounding. The underlying maths is: Balance compounds monthly on the sum of your contribution and the matched portion.
What do I need to enter?
7 values: current balance, annual salary, your contribution, employer match, years to retirement, annual return, and annual raise. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the balance at retirement result mean?
It is returned as a money amount in US dollars and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
Who is this tool for?
It's built for anyone comparing money scenarios before committing — budgeting a payment, sanity-checking a quote, or seeing what a change in rate or term actually costs.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). 401(k) Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/401k
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/401k" target="_blank" rel="noopener">401(k) Calculator — RevenueLab</a> (2026).</p>
Source: [401(k) Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/401k) (2026).