$2,000 biweekly leaves $1,651.15
Three cuts sit between gross and the deposit: federal income tax, FICA (Social Security + Medicare), and pre-tax deductions like a traditional 401(k). The math:
- Federal withholding: the 2026 Percentage Method Tables from IRS Publication 15-T
- FICA: 6.2% Social Security (up to the $184,500 wage base) + 1.45% Medicare with no cap
- Additional Medicare Tax 0.9% (§ 3101(b)(2)) when annualized wages cross the filing-status threshold
net = gross − traditional 401(k) − other pre-tax − federal withholding − FICA − additional Medicare
federal withholding wages = gross − pre-tax deductions
FICA wages = gross − Section 125/HSA deductions (401(k) still counts!)
Worked example: $2,000 → $1,651.15
Single, biweekly (26 periods), gross $2,000, no 401(k), Step 2 not checked:
- Federal withholding: annualized $52,000 → $195.85 per period
- FICA: $2,000 × 7.65% = $153.00 ($124 SS + $29 Medicare)
- Additional Medicare: $0 (under the $200,000 threshold)
- Take-home: $1,651.15, about 82.6% of gross
With a 10% traditional 401(k) the same gross nets $1,475.15 (401(k) $200 + FIT $171.85 + FICA $153).
| Scenario (single, 26×) | Gross | 401(k) / pre-tax | FIT | FICA | Net |
|---|---|---|---|---|---|
| Default, no 401(k) | $2,000 | $0 | $195.85 | $153.00 | $1,651.15 |
| 10% traditional 401(k) | $2,000 | $200 | $171.85 | $153.00 | $1,475.15 |
| Medical/HSA $150 | $2,000 | $150 | $177.85 | $141.53 | $1,530.62 |
The 401(k) catch most people miss
A traditional 401(k) deferral lowers your federal income tax, but it does not lower FICA. Social Security and Medicare still apply to the money you defer. Medical premiums under a Section 125 cafeteria plan (and HSA) do lower FICA wages. That asymmetry is why two $200 pre-tax deductions can show up differently on your paycheck stub.
| Deduction type | Lowers FIT | Lowers FICA | Net on $2,000 |
|---|---|---|---|
| Traditional 401(k) 10% ($200) | Yes → FIT $171.85 | No → FICA $153 | $1,475.15 |
| Medical/HSA $150 (§ 125) | Yes → FIT $177.85 | Yes → FICA $141.53 | $1,530.62 |
| No deductions | FIT $195.85 | FICA $153 | $1,651.15 |
Other 2026 reference points
| Profile | Gross / frequency | FIT | FICA | Net |
|---|---|---|---|---|
| Single | $2,000 biweekly | $195.85 | $153.00 | $1,651.15 |
| Married filing jointly | $5,000 biweekly | $529.92 | $382.50 | $4,087.58 |
| Single | $3,000 monthly | $264.33 | $229.50 | $2,506.17 |
This estimate uses 2026 Pub 15-T + FICA + Additional Medicare Tax 0.9% when it applies. It includes W-4 Step 3 credits and Step 4(c) extra withholding if you enter them. It excludes Step 4(a) other income, Step 4(b) itemized deductions, Roth 401(k) (after-tax), and all state or local taxes. Educational estimate from IRS Pub 15-T (Rev. Dec. 2025) and 26 U.S.C. § 3101; not tax advice.
Official sources
- IRS Publication 15-T (2026): percentage method tables
- IRS Topic No. 751: Social Security and Medicare withholding rates
- Form W-4 (2026)
Related tools (United States):
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Washington / Nevada paycheck: $90,000 biweekly leaves $2,702.04
-
Weekly $1,200 ($62,400) leaves $977.62
-
Semimonthly $3,000 ($72,000) leaves $2,399.58
-
Effective tax on $120,000: 16.33%, last dollars 24%
-
Monthly $8,000 ($96,000) leaves $6,206.17
-
Biweekly $1,846.15 ($48,000) leaves $1,527.54
-
HOH $3,230.77 ($84,000) leaves $2,677.46
-
Effective tax on $180,000 married: 13.77%, last dollars 22%
-
Hourly $15 × 40 ($600) leaves $504.18
-
Effective tax on $140,000 HOH: 14.75%, last dollars 24%
-
Married joint $4,153.85 ($108,000) leaves $3,445.77
Single, no 401(k), Step 2 off: federal withholding $195.85 + FICA $153.00 → net $1,651.15 (≈82.6% of gross). With a 10% traditional 401(k) net falls to $1,475.15.
No. Traditional 401(k) deferrals lower federal income tax withholding but are still subject to Social Security and Medicare. Only pre-tax deductions like medical premiums (Section 125) or HSA reduce FICA wages. On $2,000 with 10% 401(k), FICA stays $153.
On $2,000 biweekly single, $150 medical/HSA drops FIT to $177.85 and FICA to $141.53 → net $1,530.62. Unlike 401(k), that deduction does reduce the FICA base.
State/local taxes, W-4 Step 4(a)/(b), or a Roth 401(k) may be missing. This tool already models Step 3, Step 4(c), FICA, and Additional Medicare Tax 0.9%. It is an educational estimate, not tax advice.
- Hourly $20 × 40 ($800) leaves $664.88