How ExactTakeHome Calculates Your Paycheck
ExactTakeHome computes paycheck estimates in your browser using IRS Pub 15-T, FICA data, and official state withholding sources for tax year 2026.
Order of operations
- Gross income: annual salary divided by pay periods.
- Subtract pre-tax deductions: 401(k), HSA, and other pre-tax amounts.
- Federal taxable wages equal Step 1 minus Step 2.
- Apply IRS Pub 15-T percentage method tables to Step 3.
- FICA is applied to gross wages and is not reduced by traditional 401(k) contributions.
- Apply state withholding tables to state taxable wages.
- Net pay equals gross pay minus all taxes and all deductions.
Federal withholding
Federal income-tax withholding uses the IRS Pub 15-T percentage method. Traditional 401(k) and HSA inputs are subtracted before federal taxable wages are computed when the applicable payroll treatment reduces federal taxable wages. Some competing tools skip this pre-tax ordering step for 401(k), which can over-estimate federal withholding.
FICA
Social Security is 6.2% on the first $184,500 of wages for 2026, using the source-backed wage base encoded in the repo data. Medicare is 1.45% on all wages. Additional Medicare is 0.9% above $200,000 for single filers and $250,000 for married filers.
State withholding
Each state uses its own Department of Revenue withholding tables or equivalent official payroll method. ExactTakeHome covers all 50 states plus DC, with limitations documented where a state's official method requires additional employee certificate details or where support is intentionally scoped.
Show-your-math example
Example: $80,000 annual salary, single, biweekly, California, no pre-tax deductions.
| Component | Calculation | Per Period |
|---|---|---|
| Gross | $80,000 / 26 | $3,076.92 |
| Federal withholding | IRS Pub 15-T table (single, standard W-4) | ~$337.31 |
| Social Security | $3,076.92 x 6.2% | $190.77 |
| Medicare | $3,076.92 x 1.45% | $44.62 |
| CA state withholding | CA DE 4 / EDD Method B tables (single) | ~$141.65 |
| SDI (CA) | $3,076.92 x 1.3% | $40.00 |
| Net take-home | ~$2,322.59 |
Actual amounts vary based on filing status, W-4 elections, and pre-tax deductions. Use the calculator for your exact situation.
Why ExactTakeHome is more accurate
Decision D-124: 401(k) is subtracted before federal taxable wages, consistent with IRS Pub 15-T. Some widely-used calculators do not do this, resulting in over-estimated federal withholding.
Data sources
| Component | Source | Effective Date |
|---|---|---|
| Federal withholding brackets | IRS Publication 15-T (2026) | 2026-01-01 |
| Social Security wage base | Social Security Administration wage base source | 2026-01-01 |
| Medicare / Additional Medicare | IRS Publication 15 (2026) | 2026-01-01 |
| State withholding (all 50 states + DC) | Each state's Dept. of Revenue withholding tables | 2026-01-01 per state |
| FICA rates | Social Security Administration fact sheet and IRS Topic 751 | 2026-01-01 |
See also: Effective Tax Rates by State (2026) and State Income Tax Rates by State (2026).