Raise & 401(k) Paycheck Impact Calculator
This raise calculator answers "how much will I keep?" and this 401(k) calculator answers "how much will my paycheck decrease?" in one place: enter your current salary, your raise, and your old and new 401(k) rates, and it shows the new take-home pay per year and per biweekly paycheck, how much of the gross raise survives tax, and what the 401(k) increase alone costs per check. It uses the 2026 federal brackets, standard deduction, and FICA, plus the 2026 401(k) limit of $24,500 ($32,500 at 50+, $35,750 at 60–63) — so a 5% raise on $75,000 with a 401(k) jump from 5% to 10% is priced honestly: the raise is $3,750 gross, but take-home actually falls $579 because the extra $4,125 of retirement savings outweighs it.
Gross salary before tax and before 401(k) deductions.
A 5% raise and a $5,000 raise are different questions — pick the one your offer letter uses.
Percentage added to your current salary.
Share of gross pay you defer now, as a percentage of salary.
Share of gross pay you plan to defer after the raise. Set it equal to the current rate to price the raise alone.
IRS Notice 2025-67: $24,500 base, plus $8,000 catch-up at 50+, plus an $11,250 super catch-up at 60–63.
Sets the standard deduction ($16,100 single / $32,200 joint) and the Additional Medicare threshold ($200,000 / $250,000).
Raise kept per year (take-home change)
-579.38
- Current gross salaryThe salary you entered, before tax and 401(k).
- 75,000
- New gross salaryCurrent salary + $3750.00 raise.
- 78,750
- Raise (gross, per year)5% of $75000.00.
- 3,750
- Current 401(k) contribution5% of $75000.00.
- 3,750
- New 401(k) contribution10% of $78750.00.
- 7,875
- 401(k) increase (per year)New contribution minus current contribution — the extra money going to retirement.
- 4,125
- Federal income tax — before2026 brackets on $55150.00 of taxable income.
- 6,845
- Federal income tax — after2026 brackets on $54775.00 of taxable income.
- 6,762.5
- FICA tax — beforeSocial Security 6.2% (capped at $184,500) + Medicare 1.45% on the full salary — 401(k) does not reduce FICA.
- 5,737.5
- FICA tax — afterSame FICA rules on the new, higher salary.
- 6,024.38
- Take-home pay — before (per year)Current salary − current 401(k) − federal tax − FICA, before state tax.
- 58,667.5
- Take-home pay — after (per year)New salary − new 401(k) − federal tax − FICA, before state tax.
- 58,088.13
- Raise kept (per year)Take-home after minus take-home before — the part of the raise that reaches your bank account.
- -579.38
- Raise kept (% of gross raise)Raise kept ÷ gross raise. Under 100% because tax takes a slice; negative when the 401(k) increase outweighs the raise.
- -15.45%
- Biweekly paycheck — beforeTake-home before ÷ 26 pay periods.
- 2,256.44
- Biweekly paycheck — afterTake-home after ÷ 26 pay periods.
- 2,234.16
- Paycheck change per periodAfter minus before, per biweekly check — the number you will actually notice.
- -22.28
- Paycheck drop from the 401(k) increase alone (per period)Take-home at the NEW salary with the OLD 401(k) rate, minus take-home at the new salary with the NEW rate, ÷ 26. Isolates the 401(k) change from the raise.
- 118.13
- Total kept — before (take-home + 401(k))Money that stays yours before: cash in hand plus retirement savings.
- 62,417.5
- Total kept — after (take-home + 401(k))Money that stays yours after: cash in hand plus retirement savings. This rises even when take-home alone falls.
- 65,963.13
How it was calculated
- New salary: $75000.00 + $3750.00 raise = $78750.00. 401(k): $3750.00 before (at 5%) → $7875.00 after (at 10%), an increase of $4125.00 a year.
- Before: federal tax $6845.00 + FICA $5737.50 on $75000.00 less $3750.00 pre-tax = take-home $58667.50 a year ($2256.44 per biweekly check).
- After: federal tax $6762.50 + FICA $6024.38 on $78750.00 less $7875.00 pre-tax = take-home $58088.13 a year ($2234.16 per check).
- Raise kept: $58088.13 − $58667.50 = $-579.38 a year, or -15.45% of the $3750.00 gross raise. The 401(k) increase alone costs $118.13 per paycheck — less than the $158.65 per-check contribution increase, because federal tax fell with it.
How it works
The raise itself is the easy part: new salary equals old salary plus the raise, whether the raise is a percentage (salary × rate) or a flat amount. The hard part is what survives: take-home pay equals salary minus 401(k) minus federal income tax minus FICA, computed twice — once before, once after — and the difference between the two take-home figures is the raise you actually keep.
The 401(k) twist is that contributions are pre-tax for federal income tax but not for FICA. Social Security (6.2% up to the $184,500 wage base) and Medicare (1.45% on everything, plus 0.9% over $200,000 single or $250,000 joint) are charged on the full salary either way. So raising a 401(k) rate from 5% to 10% on a $78,750 salary adds $3,937.50 a year to retirement but costs only about $3,071 a year in take-home — the other $866 comes back as lower federal tax, because taxable income fell by the same $3,937.50 and the top slice of it was taxed at 22%.
That asymmetry produces the counterintuitive headline case: a 5% raise ($3,750) paired with a 401(k) jump from 5% to 10% leaves take-home $579 LOWER, even though the job pays more. Nothing went wrong — $4,125 more went to retirement, federal tax fell $82.50, and total kept (take-home + 401(k)) rose from $62,417.50 to $65,963.13. Judging a raise by take-home alone, without the retirement line, misreads the deal.
The 2026 401(k) cap shapes the top end: $24,500 of employee deferrals (IRS Notice 2025-67), $32,500 at age 50–59 with the $8,000 catch-up, $35,750 at 60–63 with the $11,250 super catch-up. A 12% rate on a $300,000 salary is $36,000 raw, which payroll caps at $32,500 for a 50-year-old — the extra $3,500 never leaves the paycheck, and the tax lines use the capped figure. The cap applies across all plans combined, not per employer.
State income tax is excluded by design, as in the hourly-salary converter: it varies by state and the take-home pay calculator already carries the full state table. Treat every take-home figure here as a ceiling before state tax, and re-run the state figure there before budgeting the raise.
Worked examples
5% raise + 401(k) from 5% to 10% on $75,000 — take-home falls, wealth rises
Gross pay rises from $75,000 to $78,750, a $3,750 raise. The 401(k) contribution rises from $3,750 to $7,875. Federal tax actually falls from $6,845 to $6,762.50 (taxable income drops from $55,150 to $54,775), while FICA rises from $5,737.50 to $6,024.38 on the higher salary. Take-home moves from $58,667.50 to $58,088.13 — down $579.38 a year, or $22.28 per biweekly check — even though the raise is real. Total kept tells the true story: $62,417.50 before versus $65,963.13 after. The 401(k) increase alone costs $118.13 per check, not the $151.44 the contribution increase suggests, because federal tax fell $866.25 a year alongside it.
$10,000 raise + starting a 6% 401(k) on $100,000 — how much of the raise survives?
Gross pay rises from $100,000 to $110,000. With no 401(k) before and 6% ($6,600) after, filing jointly, federal tax moves from $7,640 to $8,048 and FICA from $7,650 to $8,415. Take-home rises from $84,710 to $86,937 — only $2,227 of the $10,000 raise reaches the bank account, 22.27% of it, because $6,600 went to retirement and $1,173 went to extra tax. The biweekly check rises $85.65, from $3,258.08 to $3,343.73. The 401(k) alone costs $223.38 per check at the new salary — but total kept rises from $84,710 to $93,537, which is the number to compare against the old job, not the paycheck alone.
How to measure
- Price the raise and the 401(k) change separately before judging either: set the new 401(k) rate equal to the current rate to see the raise alone, then raise the rate to see the 401(k) cost alone. The "paycheck drop from the 401(k) increase alone" row does the second step for you at the new salary.
- Enter the raise the way your offer letter states it: a 5% raise on $75,000 is $3,750, but a $5,000 raise on the same salary is 6.67% — mixing the two overstates or understates the new salary by thousands. Use the percentage mode for percentage offers and the amount mode for flat offers.
- Compare total kept, not take-home, when a 401(k) change is involved: take-home can fall while total kept rises by thousands, because retirement money is still yours. Only compare take-home to take-home when the 401(k) rate is unchanged.
- Check the IRS cap before assuming a high rate sticks: 12% of $300,000 is $36,000, above the $32,500 limit at age 50–59, so $3,500 of it never leaves the paycheck. If you hold two jobs with 401(k)s, the cap applies across both combined — payroll at one job cannot see the other.
- Remember the FICA asymmetry when estimating by hand: a quick rule is that each extra pre-tax 401(k) dollar costs roughly (1 − your marginal federal rate) dollars of take-home — about $0.78 at the 22% bracket, $0.76 at 24% — never the full dollar, and never less than the FICA bite, which the contribution does not avoid.
- Re-run with your state in the take-home pay calculator before budgeting: state tax comes out of the same check and is excluded here, so a high-tax state can take another slice of the raise that this page does not show.
Assumptions & limitations
Planning estimate
- Tax year 2026 throughout: federal brackets and standard deduction from IRS Revenue Procedure 2025-32, FICA from the 2026 SSA wage base, 401(k) limits from IRS Notice 2025-67. Figures for other years will differ.
- 401(k) contributions are pre-tax for federal income tax only. Roth 401(k) contributions, which are after-tax, are NOT modeled — a Roth rate would leave federal tax unchanged and cost the full contribution in take-home.
- Contributions above the IRS limit are capped at the limit for the tax lines, matching payroll behavior. The cap is applied per scenario, not tracked across multiple employers.
- State income tax is excluded entirely, as in the hourly-salary converter. Use the take-home pay calculator for a state-by-state figure.
- Employer matching contributions are NOT included: a match is free money on top of your deferral, not a deduction from your paycheck, so it does not change take-home — but it does change whether cutting your rate is a good idea, which the warning flags.
- Paychecks are biweekly (26 periods). Monthly budgeting from a biweekly check overstates a normal month — two months a year have three checks.
- This is a planning estimate, not tax or financial advice. Confirm a raise, a contribution change, or a limit question with your payroll department or a tax professional.
Frequently asked questions
Less than the gross raise, and the gap depends on your 401(k) change. On a $100,000 salary with a $10,000 raise and a new 6% 401(k), only $2,227 of the raise reaches take-home — 22.27% — because $6,600 went to retirement and $1,173 to extra tax. With the 401(k) rate unchanged, the same $10,000 raise would keep roughly $7,000–$7,800 after federal tax and FICA, before state tax. Enter your own numbers above; the "raise kept" rows show both the dollars and the percentage.
Less than the contribution increase, because pre-tax deferrals also cut federal tax. Raising a 401(k) from 5% to 10% on a $78,750 salary adds $3,937.50 a year ($151.44 per biweekly check) to retirement, but the check only falls $118.13 — federal tax fell $866.25 a year alongside it. The "paycheck drop from the 401(k) increase alone" row isolates exactly this number at your salary and rates. Note the drop is never zero: 401(k) contributions do not reduce Social Security or Medicare tax.
Yes, when a 401(k) increase outweighs the raise after tax. A 5% raise on $75,000 ($3,750) paired with a 401(k) jump from 5% to 10% ($4,125 more to retirement) drops take-home by $579 a year, even though gross pay rose. Total kept still rises — from $62,417.50 to $65,963.13 — because the missing money went to your retirement account, not to tax. If take-home alone falls with no 401(k) change, check for a payroll error or a benefits change.
$24,500 of employee elective deferrals for 2026 (IRS Notice 2025-67, announced November 13, 2025), up from $23,500 in 2025. Workers age 50 or older may add an $8,000 catch-up for $32,500 total, and workers ages 60–63 get an $11,250 super catch-up for $35,750 total. The limit applies across all your plans combined, not per employer, and it covers your own deferrals only — employer matches sit under a separate $72,000 total cap.
No. 401(k) deferrals are pre-tax for federal (and usually state) income tax, but Social Security tax (6.2% up to the $184,500 wage base) and Medicare tax (1.45%, plus 0.9% over $200,000 single or $250,000 joint) are charged on your full salary. That is why a $100 monthly 401(k) increase cuts take-home by roughly $78 at the 22% bracket rather than $100 — the income-tax saving, not a FICA saving.
On total kept (take-home + 401(k)) when the 401(k) rate differs, and on take-home when it does not. Two offers with the same gross salary can show different paychecks purely because one defers more to retirement — the higher paycheck is not the better deal if the other offer banks thousands more in a matched 401(k). Compare the same lines on both offers, then weigh the match, vesting, and benefits on top.