401(k) Calculator
It projects a 401(k) balance to retirement including the employer match, annual raises and the contribution limit, and flags any match you are not claiming.
Balance after 30 years
$1,183,419
Your contributions
$194,727
Employer match
$129,818
Investment growth
$833,875
Final balance
$1,183,419
This year you add
$4,800
Deferral limit
$24,500
A projection, not investment advice. Returns are not guaranteed, and check your vesting schedule — unvested employer money is forfeited if you leave early.
What it calculates
It projects a 401(k) balance to retirement including the employer match, annual raises and the contribution limit, and flags any match you are not claiming.
Why it matters
The employer match is the highest guaranteed return available anywhere, and contributing below the match threshold declines part of your own salary.
Who it's for
Anyone with a workplace retirement plan deciding what percentage to contribute, and savers checking whether they are on track.
Formula
- S
- Annual salary
- c
- Your contribution as a percent of salary
- m
- Employer match rate and the cap it applies to
- r
- Expected annual return
Worked example
$80,000 salary, 6% contribution, full match to 4%
- 1You contribute 80,000 × 6% = $4,800 a year
- 2The employer adds 80,000 × 4% = $3,200
- 3Both grow at 7% for 30 years
About $808,600, of which $96,000 came from the employer
How the 401(k) calculator works
Your contribution is a percentage of salary, capped each year by the IRS elective deferral limit. The employer match applies only to the portion of your contribution inside their cap, so contributing above it adds your money but earns no further match. Everything compounds together at the assumed return. The single most consequential input is the contribution percentage relative to the match threshold: contributing less than the employer will match declines free money, and no investment return makes up for it.
The employer match applies only to the part of your contribution inside their cap. Contributing above it adds your money but earns no further match, which is the most common misunderstanding about a 401(k).
Contributing less than the employer will match declines part of your own compensation, and no investment return makes that up.
Common mistakes
- Contributing below the match threshold and leaving guaranteed money unclaimed.
- Assuming a higher contribution earns a bigger match once you pass the employer's cap.
- Overlooking vesting, which can mean leaving before the employer's contributions are truly yours.
- Modelling an optimistic return and treating the projection as a promise.
Tips and best practice
- Contribute at least up to the full match before considering any other investment.
- Raise the contribution percentage with each pay rise, before the money reaches your account.
- Check the vesting schedule before changing jobs; unvested employer money is forfeited.
Frequently asked questions
How much should I contribute to my 401(k)?
At minimum, enough to earn the full employer match. Beyond that, 10–15% of salary including the match is a common target for retirement readiness.
How does employer matching work?
The employer contributes a percentage of what you put in, up to a cap stated as a percentage of salary. Contributing above that cap earns no further match.
What is the 401(k) contribution limit?
The IRS sets an annual elective deferral limit, with an additional catch-up amount for those aged 50 and over. Employer contributions sit outside that limit.
What happens if I contribute more than the match?
The extra is still yours and still grows tax-deferred, but the employer contributes nothing further on it. The match stops at their stated cap.
What is vesting?
The schedule that determines when employer contributions become irrevocably yours. Leaving before you are fully vested forfeits the unvested portion.
Related calculators
Methodology & trust
- Formula source
- IRS elective deferral limits for 2026 and standard employer match structures
- Last updated
- 2026-07-28
- Privacy
- Every calculation runs in your browser. No inputs are sent to a server or stored.