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401(k) employer match calculator

Most 401(k) calculators show you a future-value number. This one shows you the number that should actually drive the decision: how much free employer money you're declining by contributing below the match cap. Often the answer is several thousand dollars a year — which compounds.

Last updated 2026-05-13

What HR puts on your offer letter — match is computed as % of this number.
Aim to at least hit the cap below — every dollar under is match left on the table.
Employer match formula
Check your benefits portal or summary plan description for your exact formula.
You are leaving $1,200 per year of employer match on the table.Match left on the table — per year
You're capturing 50% of available match. Bump to 6% of salary to claim all of it.

Your contribution
$2,400/yr
Employer match (actual)
$1,200/yr
Maximum employer match
$2,400/yr
Total going into 401(k)
$3,600/yr

Over 30 years at 7.00%
Employer match alone, compounded
$121,997
Match left on the table, compounded
$121,997
Total 401(k) balance
$365,991
Bottom line: bumping your contribution from 3% to 6% claims an extra $1,200/year in free employer money — which compounds to $121,997 by retirement. No raise needed, no investing skill required.
Methodology

What this calculator does (and what it deliberately doesn't)

Why match-left-on-table is the headline: the employer match is one of the few risk-free, ~100% guaranteed returns available to a typical worker. Skipping it to fund anything other than emergency cash or high-rate debt is almost always wrong. We make the dollar figure unmissable.

The four preset formulascover the most common shapes observed across US employer plans. Yours may differ — check your benefits portal or summary plan description. If your formula doesn't fit any preset, pick the closest one and adjust the contribution slider until the match-captured number matches your last paystub.

The compounding uses 7% / monthly by default, matching the S&P 500 long-run real return. Lower it to 4-5% if you want a more conservative projection, or to model a balanced (60/40) portfolio.

Vesting isn't modeled.Many employer matches vest on a schedule — typically 3-year cliff or 6-year graded. If you leave before vesting, the match portion can be forfeited. The numbers here assume you eventually vest fully. If you're job-hopping inside a vesting window, discount accordingly.

IRS limits aren't modeled.In 2026, the employee elective deferral cap is $23,000 ($30,500 with catch-up if 50+). Combined employee + employer cap is $69,000. At typical salaries and match formulas these limits don't bind — but for high earners or aggressive savers, they can.

Taxes aren't modeled either.Traditional 401(k) contributions reduce taxable income now and are taxed on withdrawal. Roth 401(k) contributions are after-tax going in and tax-free coming out. Employer match always goes into the pre-tax bucket regardless of whether you chose Roth or Traditional. For the match-capture decision this doesn't matter — getting taxed later is still better than not getting the dollars at all.

If you can't afford to hit the cap right now:that's a real constraint, and it's rational to prioritize cash flow / debt payoff / emergency savings first. The framework is: capture the full match first if at all possible, because every other tax-advantaged dollar (HSA, IRA) generally gets matched at 0%.

What about the "match true-up" problem?Some employers match per-paycheck (so if you front-load your contribution, you hit the elective cap mid-year and miss matches on the remaining paychecks). Most large plans do an annual true-up that fixes this, but smaller plans sometimes don't. If yours doesn't, spread contributions evenly across the year rather than front-loading.

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