401K Calculator

This site has three retirement tools that all model the same underlying idea — money growing tax-advantaged until you retire — but each one answers a different question, and it's easy to grab the wrong one. Use this 401(k) Calculator when your money is going into a workplace plan with an employer match, because it's the only one of the three that models a match formula and a rising salary. Use the IRA Calculator when you want Traditional, Roth, and a plain taxable account compared side by side in one chart — that's what it's built for. And use the Roth IRA Calculator once you've already decided on a Roth-style account and want the after-tax contribution math worked through on its own, without the taxable-account comparison in the way.

How the Match Formula Actually Works

Each year, this tool computes two contribution figures from your salary: your own contribution equals Salary × Contribution %, and your employer's contribution equals Salary × whichever is smaller, your Match % or your Match Limit %. That "smaller of" step matters — if your employer offers a 50% match up to 6% of salary, contributing 10% of your own salary doesn't get you a bigger match; you're still only matched on the first 6%.

Worked example: a $60,000 salary, contributing 5%, with a 3% employer match capped at a 6% limit, a $10,000 starting balance, and a 7% return.

• Employee contribution: 60,000 × 5% = $3,000
• Employer contribution: 60,000 × smaller of (3%, 6%) = $1,800
• Interest at 7% on (10,000 + 3,000 + 1,800): roughly $1,036
• Balance after year one: roughly $15,836

After that, your salary grows by whatever salary-increment rate you set, and the same three steps repeat for the next year.

Frequently Asked Questions

Q: I set my employer match higher than the match limit — why doesn't the match number change?

The formula always uses the smaller of your Match % and your Match Limit %, since that's how real 401(k) plans cap their contribution. An employer offering a large match percentage but capping it at a lower percentage of salary will never match beyond that cap, no matter what number you type into the match field.

Q: Does this account for the IRS annual contribution limit?

No — the calculator applies your contribution percentage to your rising salary every year without checking it against the IRS elective-deferral cap. At higher salaries and contribution percentages in later years, check your numbers against the current IRS limit separately, since this tool won't stop you from exceeding it.

Q: How is the "adjusted for inflation" figure calculated?

It takes your total nominal balance at retirement and divides it by one plus your inflation rate, raised to the number of years you're saving — the same discounting math used to turn a future dollar amount into today's purchasing power.

Q: My salary increment is set to 0% — is that a valid scenario?

Yes. Setting it to 0% simply holds your salary flat for the entire projection, which is a reasonable conservative case to run alongside a more optimistic growth assumption.