Documented model
How the estimate is built
PayNetUS uses a published-bracket annual method, then divides by the number of pay periods. That is close in spirit to the IRS Publication 15-T percentage method, but it is not a copy of any employer’s payroll engine and is not an official withholding table.
1. Annualize gross
- Salary: the annual salary you enter.
- Hourly: hourly rate × hours per week × 52.
Per-check gross is annual gross ÷ periods (52, 26, 24, 12, 4, or 1).
2. Traditional 401(k)
Optional pre-tax deferrals reduce federal and state taxable wages. They do not reduce Social Security or Medicare in this model, which matches typical elective deferral treatment. Roth 401(k) is not modeled. Plan limits are warned, not hard-enforced.
3. Federal income tax TY 2025 / 2026
Subtract the standard deduction for the selected filing status, apply the seven federal brackets, then subtract a simplified Child Tax Credit of $2,200 per dependent. No itemizing, no other income, no multiple-jobs adjustment, no EITC, no premium tax credit, no AMT, no phaseouts.
2026 standard deduction: single / MFS $16,100 · MFJ $32,200 · HOH $24,150
2025 standard deduction (OBBBA): single / MFS $15,750 · MFJ $31,500 · HOH $23,625
IRS Rev. Proc. 2025-32 (tax year 2026 inflation adjustments, including OBBBA amendments). IRS tax year 2025 rate schedules (Rev. Proc. 2024-40; standard deduction as amended by P.L. 119-21 / OBBBA).
2026 federal brackets (taxable income)
| Rate | Single from | MFJ from | HOH from |
|---|---|---|---|
| 10% | $0 | $0 | $0 |
| 12% | $12,400 | $24,800 | $17,700 |
| 22% | $50,400 | $100,800 | $67,450 |
| 24% | $105,700 | $211,400 | $105,700 |
| 32% | $201,775 | $403,550 | $201,775 |
| 35% | $256,225 | $512,450 | $256,200 |
| 37% | $640,600 | $768,700 | $640,600 |
4. FICA
- Social Security: 6.2% of wages up to $176,100 (2025) or $184,500 (2026).
- Medicare: 1.45% of all wages.
- Additional Medicare: 0.9% above $200,000 single/HOH, $250,000 MFJ, $125,000 MFS.
SSA 2026 OASDI wage base $184,500; employee SS 6.2%, Medicare 1.45%, Additional Medicare 0.9%. Employers generally begin withholding Additional Medicare at $200,000 of wages regardless of filing status; the estimate uses the liability threshold by status.
5. Simplified state wage tax
State figures use 2026 published structures compiled from Tax Foundation state rate tables (as of January 2026): flat rates or graduated brackets, plus a single/joint standard deduction and personal or dependent exemption or credit where those are simple enough to encode. Head of household and married filing separately use the single-style state deduction and brackets unless a joint table exists (joint is used only for MFJ).
No wage income tax in this model: Alaska, Florida, New Hampshire, Nevada, South Dakota, Tennessee, Texas, Washington, Wyoming.
Intentionally omitted:
- City, county, school-district, and occupational taxes
- SDI / PFML / WA Cares and similar payroll programs
- Recapture, benefit add-backs, and most credit phaseouts
- Part-year residency, reciprocity, and nonresident allocation
Each result shows a short state note. If your locality has a wage tax, your stub will be lower than this estimate.
6. Net pay
Net = gross − 401(k) − federal income tax − Social Security − Medicare (including Additional Medicare) − state income tax. Never below zero in the display.
Sources
- IRS, “IRS releases tax inflation adjustments for tax year 2026” and Rev. Proc. 2025-32
- IRS federal income tax rates and brackets (tax year 2025)
- SSA contribution and benefit base (2025: $176,100; 2026: $184,500)
- Tax Foundation, 2026 state individual income tax rates and brackets
Official publications control if they disagree with this page. This is not tax advice and not an IRS or state tool.