Calculator · 401(k)

How much free money are you walking past?

If your employer offers a 401(k) match and you contribute less than the cap, you're leaving part of your compensation on the table. Punch in your numbers — see what the gap costs over a decade.

Background Read the 401(k) guide

Sample numbers below — edit any field to make them yours.

Annual salary gross — before taxes & deductions The number on your offer letter. The match is calculated against this, not your take-home.

$

Your contribution 401(k) deferrals always run on gross pay The percentage of each paycheck you elect to send to the 401(k). Contributing below the match cap means leaving free money on the table.

% of gross

Match rate For every $1 you put in, your employer adds this share — e.g., "100%" means dollar-for-dollar.

%

Up to The contribution cap your employer matches against. Above this, you can still contribute — they just don't add more.

% of gross

Two-tier match e.g., 100% to 3%, then 50% to 5%

Employer matches 100% of your contribution, up to 6% of your gross salary.

Projection 10 yrs · 7% return

Project over How long until you'd stop or change plans. Most people set this to "how long I'll be at this employer."

years

Assumed return 7% is a careful long-run estimate for stocks after inflation. Real returns vary year to year.

% / yr

The match is part of your pay. Contributing below the cap is choosing to leave it.

You contribute —

Employer adds —

Total at year 10 @ 7%

—

Your contributions + employer match, with growth

Your money —

Employer match —

Missing — in match each year — bumping to — would capture another — over 10 yrs.

Capturing the full employer match. Contributing more still grows your savings, but the employer won't add beyond the cap.

This plan doesn't offer an employer match. Your projected balance is just your own contributions, growing.

Estimates only. Annual contributions spread evenly across 12 months, monthly compounding, constant return, salary held flat. Real plans vest, cap differently, and markets vary. Your plan documents are the source of truth.

How to read it

The match is part of your pay.

When a job offer says "401(k) with 100% match up to 6%," they're saying: contribute 6% of your salary and the company will add another 6%. If you only contribute 3%, the company only adds 3%. Half of the match disappears — not into a savings account, not into your paycheck. It just doesn't get earned.

Plain English

A "100% match up to 6%" means: your employer matches every dollar you put in, dollar for dollar, until your contribution hits 6% of your salary. Past 6%, you're on your own.

Common match formulas

Three you'll actually see.

Match formulas vary by employer. The three patterns below cover most plans. To find yours, look at your benefits portal or plan summary — it'll be phrased something like "100% of the first 4% and 50% of the next 2%."

100% up to 6%. Set match rate to 100 and cap to 6. Generous; common at larger employers.
50% up to 6%. Set match rate to 50 and cap to 6. You'd need to contribute 6% to get a 3%-of-salary match.
100% up to 3%, then 50% up to 5%. "Tiered" formulas can't be modeled with one slider. Approximate by entering the cap (5%) and a blended rate (~80%) — or check your plan documents for the exact figure.

Caveats

Where this estimate is rough.

Vesting. Some plans require you to stay X years before the match is fully yours. The calculator assumes you stay long enough to vest.
Contribution timing. Real matches are deposited per paycheck; the projection assumes year-end for simplicity. The difference over a decade is small.
Returns vary. 7% is a common long-run assumption for diversified equities. Real returns are bumpy. The projection shows trajectory, not promise.
IRS limits. If you're a high earner, the IRS contribution and compensation caps may bind before the match cap does. See the 401(k) guide.

Next read

Want the rest of the picture?

The full 401(k) guide covers traditional vs. Roth, vesting schedules, what happens when you change jobs, and the IRS limits for the current year.

Read the 401(k) guide → Ask about your plan