Educational reference only. 2025 limits cited from IRS Notice 2024-80. Updated January 2025.
Step 1 of 3
Five inputs, and the match math updates as you type. The values stay in this browser tab.
Employer match = min(your rate, plan cap) x eligible pay x match rate. How the formula works
Checked when the cap you entered matches your plan document, not last year's payroll default.
Calculated output
These rows recalculate as you change gross pay, contribution percentage, and your plan formula above. Your own deferral stops at the 2025 elective limit of $23,500.
$3,800
$1,900
$950
$5,700
$836
$146
Estimate only. It ignores state tax, payroll tax, and plan-specific compensation definitions. Read the assumptions and the 2025 limits ledger before you set a rate.
Checked: I compared my deferral rate against my plan match cap using this output.
Scenario delta
Sample plan inputs: $85,000 eligible pay, employer match of 100% on the first 4% of pay, 22% assumed marginal federal rate. Every delta is measured against the do-nothing row.
Rows shown in the default order.
| Scenario | Deferral rate | You contribute | Employer match | Total invested | Take-home pay | Est. tax saved | Delta in total invested |
|---|---|---|---|---|---|---|---|
| Do nothing | 0% | $0 | $0 | $0 | $66,300 | $0 | baseline |
| Capture full match | 5% | $4,250 | $3,400 | $7,650 | $62,985 | $935 | +$7,650 |
| Max out 402(g) | 27.6% | $23,500 | $3,400 | $26,900 | $47,970 | $5,170 | +$26,900 |
Annual figures, single filer, before state tax. The max-out row uses the 2025 elective deferral limit of $23,500 before any catch-up, so an IRA at $7,000 or an HSA at $4,300 self-only could still be stacked on top and each one moves the take-home column.
I have replaced the sample $85,000 salary with my own pay in the calculator inputs above.
Assumptions
The calculator works with federal figures and the numbers you type in. It does not model state tax, plan documents, or how markets behave over the years you hold an account.
State and local tax
Not modelledA few states tax no wage income, most tax it at their own rates, and some cities add a local tax on top. Deferring income shifts the federal bill only. Your state treatment can change the picture in either direction.
Your plan's rules
Not modelledMatch formulas, caps, vesting schedules, eligibility waiting periods, and true-up timing vary by employer. The results assume the formula you entered applies to all eligible pay with no plan cap on the match itself.
Investment return and fees
Figures are contribution and tax math, not growth projections. No assumed rate of return, no expense ratios, and no advisory fees are applied to any balance.
Withdrawal tax rates
Deductions today are weighed against an unknown future rate. Every figure reflects current-year federal rates only; it assumes no penalty, no early distribution, and no required minimum distribution.
Payroll timing
Contributions are treated as spread evenly across the year so the full match is captured. A front-loaded deferral that hits the elective limit in, say, September can trigger a plan-specific true-up or a partial match.
Other income and phase-outs
Modified adjusted gross income, filing status, spousal coverage, and other deductions all move deductibility thresholds and credit eligibility. None are applied here.
Checked: I have read my plan's summary description for the match formula and vesting schedule before treating any output above as mine.
Numbers off because an input was wrong? Return to the calculator inputs and rerun the three scenarios.