401(k) Calculator With Employer Match
A 401(k) is the workplace retirement account most US employers offer. Money is deducted straight from your paycheck, invested in funds you choose, and — crucially — many employers match part of what you put in. That match is the closest thing to free money in personal finance, and it is the single biggest reason to contribute at least enough to capture all of it.
This calculator models the three forces that build a 401(k): your own contributions, the employer match, and investment growth compounding on top of both. Take the default scenario — a $80,000 salary, contributing 10% of pay, with the employer matching 50% of contributions up to 6% of salary, an illustrative 7% annual return, 2% yearly raises, and a $20,000 starting balance. After 30 years the balance grows to $1,443,292. Of that, $324,545 came out of your paychecks, $97,363 was contributed by your employer, and $1,001,384 — about 69% of the total — is pure investment growth.
The employer match matters enormously. In year one alone, contributing 10% of an $80,000 salary means you put in $8,000 and your employer adds $2,400 on top — an instant 50% return before the market does anything. One caveat governs the whole page: the 7%/year return is an illustrative assumption, not a promise. Real returns vary year to year and can be negative; past performance does not guarantee future results.
How the calculator projects your 401(k)
The year-by-year model
The tool simulates one year at a time so you can see exactly how the balance grows. Each year, in order:
- Your contribution = salary × contribution rate.
- Employer match = salary × min(contribution rate, 6%) × match rate. The match only applies to the first 6% of salary you contribute — that is the typical "matches up to 6%" cap.
- Growth = the new balance (old balance + your contribution + match) earns the annual return.
- Raise = your salary grows for the next year.
| Symbol | Meaning | Default |
|---|---|---|
| Starting balance | What you already have in the 401(k) | $20,000 |
| Salary | Gross annual salary (grows each year) | $80,000 |
| Contribution rate | Share of salary you contribute | 10% |
| Match rate | Cents the employer adds per dollar you contribute | 50% |
| Match cap | Salary share the match applies to | 6% |
| Return | Assumed annual investment return | 7% |
| Raise | Annual salary growth | 2% |
Why the match is the headline
Because the match is a fixed percentage of what you contribute, it is a guaranteed, immediate return on your own money — independent of the market. At a 50% match on the first 6% of an $80,000 salary, that is $2,400 of employer money in year one. Contributing below the cap leaves part of that match unclaimed; contributing above the cap still helps your balance, but those extra dollars earn no additional match.
What the model leaves out
The calculator assumes a constant, positive return every year; real markets are volatile and have negative years. It also ignores 401(k) contribution limits (the IRS caps annual elective deferrals), vesting schedules (some employer matches are not fully yours until you have stayed a few years), taxes on eventual withdrawals, fees, and inflation. Treat the result as a clean scenario for building intuition, not a precise forecast — and re-run it with a lower return to stress-test your plan.
Worked example: $80,000 salary, 10% contribution, 50% match
Illustrative assumptions: a constant 7%/year return, 2% annual raises, a 50% employer match on the first 6% of salary, and a $20,000 starting balance.
Year one mechanics. You contribute 10% of $80,000 = $8,000. Your employer matches 50% of the first 6% of salary (6% of $80,000 = $4,800) — that is $2,400. The $20,000 you started with plus $10,400 of new money then grows 7%, ending year one at $32,528.
| Milestone | Your contributions | Employer match | Investment growth | Balance |
|---|---|---|---|---|
| Year 10 | $87,598 | $26,279 | $71,976 | $205,853 |
| Year 20 | $194,379 | $58,314 | $335,226 | $607,918 |
| Year 30 | $324,545 | $97,363 | $1,001,384 | $1,443,292 |
Three things stand out.
- Growth eventually dominates. By year 30, investment growth of $1,001,384 is about 69% of the $1,443,292 balance — far more than the $324,545 you contributed.
- The match is real money. Over 30 years your employer adds $97,363 on top of your own contributions — money you would forfeit by contributing too little.
- Time does the heavy lifting. The early dollars, both yours and the match, have three decades to compound, which is why starting young beats trying to catch up later.
Re-run the calculator with your own salary, contribution rate and a return you consider realistic. FiMo also has compound-interest and retirement-savings tools if you want to compare a 401(k) against other accounts.
Frequently asked questions
How does a 401(k) employer match work?
An employer match means your company contributes extra money based on what you put in. A common formula is a 50% match up to 6% of salary: for every dollar you contribute, the employer adds 50% cents, but only on contributions up to 6% of your pay. On an $80,000 salary that is $2,400 of free money in year one. Contributing less than 6% leaves part of that match unclaimed, so capturing the full match is usually the first priority.
How much will my 401(k) be worth in 30 years?
It depends on your salary, contribution rate and the return — which nobody can predict. In the default scenario ($80,000 salary, 10% contribution, 50% match up to 6%, $20,000 starting balance) at an illustrative 7%/year, the balance grows to about $1,443,292 after 30 years. Of that, $324,545 is your contributions, $97,363 is the employer match, and $1,001,384 is investment growth. Enter your own figures for a result that fits your situation.
How is the 401(k) projection calculated?
The calculator runs one year at a time. Each year it adds your contribution (salary × 10%), adds the employer match (salary × min(contribution rate, 6%) × 50%), then grows the whole balance by the annual return; your salary then rises for the next year. Verifiable from the table: a $80,000 salary contributes $8,000 in year one with a $2,400 match, ending year one at $32,528.
Should I contribute more than the match cap?
Capturing the full match comes first — that is a guaranteed 50% return you cannot get elsewhere. Beyond 6%, extra contributions no longer earn a match, but they still grow tax-advantaged and compound, so contributing more is often still worthwhile up to the IRS annual limit. Whether to go further depends on your other goals (emergency fund, debt, a home). The point is never to contribute less than the cap, because that forfeits free money.
Is the 7% annual return guaranteed?
No. The 7%/year used throughout this page is an illustrative assumption to keep the math easy to follow, not a promise or forecast. 401(k) balances are invested in funds whose returns vary year to year and can be negative, and past performance does not guarantee future results. Enter a return you consider realistic for your fund mix, and always stress-test a lower figure to see how sensitive your retirement plan is to weaker markets.
What does this 401(k) calculator leave out?
It assumes a constant, positive return every year, so it ignores market volatility and negative years. It also leaves out the IRS annual contribution limit, vesting schedules (some employer match is not fully yours until you have stayed a few years), taxes on withdrawals in retirement, account fees and inflation. Treat the projection as a clean scenario for building intuition rather than a precise prediction of your final balance.