Inputs

Annual salary (pre-tax)

Your contribution rate (% of salary) A 15% deferral is a common plan ceiling. Annual contribution limit ($)

Reference figure: a typical $23,500 federal limit for 2025, plus catch-up room over 50. Check current IRS limits.

Employer match formula

Match rate (% of your contribution) Match cap (% of salary) Typical: "50% of the first 6% you contribute." Full match then needs 12%. Annual employer match cap ($)

Long-term assumptions

Years of contributions Annual salary growth % Annual investment return % Marginal tax rate %

Return and tax rate are assumptions, not predictions.

Current account balance ($)

Full vesting period (years) Leaving before you vest forfeits part of the balance.

All math runs in your browser. Inputs are not sent anywhere.

Key numbers

First-year contribution

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First-year employer match

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Rate needed for full match

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Ending account balance

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Total employer match

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Total tax deferred

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Match status

Pre-tax deferral vs Roth

Same return on both sides; only the tax timing differs.

Where the balance comes from

Blue is the balance, gray your contributions, green the employer match.

What one more percent buys

Ending balance and extra match at +1, +3 and +5 points.

Year-by-year detail

Year	Salary	Your contribution	Employer match	Total contributed	Ending balance	Vested

How to read these numbers

It turns your contribution rate into cash, converts your match formula into the rate you need, and puts pre-tax and Roth on one table. The middle piece is the one people miss: a plan matching 50% of the first 6% needs a 12% rate, and every point below it is employer money you gave up.

Assumptions and limits

Every rate, limit and match rule here is a reference figure. Check the IRS and your plan summary.
The return is a constant assumption, not a forecast. Sequence-of-returns risk and fund fees are not modeled.
Vesting is a straight-line approximation. HSA contributions, RSU valuation, required distributions and estate tax are not modeled. Not investment advice, and no plan or fund is recommended.

FAQ

Is the match on my contribution or my salary?

Both exist. Read the plan document: "50% of your contribution" or "100% up to 6% of salary".

Will my rate miss part of the match?

Check "rate needed for the full match". Below it you give up employer money every year.

Pre-tax or Roth — which wins?

Short horizons favor pre-tax: less tax now, and the deferral is an interest-free loan. Long horizons favor Roth.

What happens at the contribution limit?

Money above the limit leaves the 401(k): usually paid back in cash and taxed that year, or routed to a Roth 401(k).

Why isn't deferred tax money saved?

A deferral only postpones tax. A higher rate later, or a job change, can mean tax plus a 10% penalty.

If I leave the job?

Unvested match is usually forfeited. Vested amounts and your own contributions are generally yours to roll over.

Where does the 6% return come from?

An assumption, not a forecast. 6% is a typical long-run order of magnitude — try 4% and 8%.

I have no 401(k) — still useful?

Yes, as a target calculator: price a job with a match, then compare it.

Methodology

Year by year: contribution = min(salary × rate, annual limit); match = min(contribution × match rate, salary × match cap, annual cap); balance advances by balance × (1 + return) + contributions. Pre-tax net value is balance × (1 − tax rate). Arithmetic only.

401(k) Contribution & Employer Match Calculator