A 401(k) grows from three engines at once: your contributions, your employer's match, and compound growth on the total — all tax-deferred until withdrawal. Because the match is literally free money and the tax deferral compounds for decades, small changes now (a higher contribution rate, capturing the full match) translate into six-figure differences at retirement. This calculator projects your balance at your chosen retirement age from your current balance, salary, contribution rate, employer match formula and expected return. It shows the year-by-year path, splits the final number into your contributions, employer contributions and growth, and flags how much of the match you are leaving on the table.
How the projection works
Each year, your contribution (a percentage of salary, grown by your assumed raise rate) plus the employer match is added to the balance, then the whole balance grows at the expected return. The 2026 employee contribution limit is $23,500 (plus $7,500 catch-up at 50+), and the calculator caps contributions there.
Example
Age 30, $40,000 balance, $90,000 salary, 10% contribution, 50% match up to 6%, 7% return, retire at 65. Projected balance: roughly $1.9 million — of which the employer match contributed about $200,000. Skipping the match would cost over $400,000 in lost balance and growth.
The employer match
A typical formula — "50% of the first 6%" — means contributing 6% of salary gets you an extra 3% from your employer. Not contributing enough to earn the full match is the most expensive common 401(k) mistake; it is an instant 50–100% return you can never get back later. Vesting schedules may delay full ownership of matched money if you leave early.
Frequently asked questions
How much should I contribute to my 401(k)?
At minimum, enough to capture the full employer match. The common rule of thumb is 15% of income (including the match) for retirement, adjusted for your age and goals.
What is 401(k) vesting?
Vesting is ownership of your employer's matched contributions. Your own contributions are always 100% yours; matched money may vest gradually over 2–6 years.
Roth or traditional 401(k)?
Traditional saves tax now and is taxed at withdrawal; Roth is taxed now and tax-free later. Roth usually wins if you expect a higher tax rate in retirement.
What happens to my 401(k) if I change jobs?
You can leave it, roll it into the new employer's plan, or roll it into an IRA. Avoid cashing out — taxes plus a 10% early-withdrawal penalty apply under 59½.