How Gross. calculates
your paycheck

1. Model assumptions

• The headline “−X% GONE” is taxes only — federal income tax, Social Security, Medicare, state, and local. 401(k) and health premiums are shown separately as “your elections” because that money is redirected (into your retirement or coverage), not taken. It is still yours.
• W-2 wages only — self-employment income, capital gains, rental income, and other non-wage income are not modeled.
• Standard deduction applied — no itemized deductions, no Schedule A.
• No credits or exemptions — child tax credit, EITC, education credits etc. are out of scope. Results will understate take-home for those who qualify.
• Resident-side local tax rates — nonresident withholding (where an employer withholds for your work city) is not modeled in v1.
• Pre-tax 401(k) reduces federal and most state taxable income — does not reduce FICA base. PA-specific 401(k) non-deductibility is a known v1 approximation.
• Section 125 health premiums (employer-sponsored) reduce both federal taxable income and FICA wages.
• HSA contributions (current-pay path only) are modeled pre-tax like 401(k) — they reduce federal, state, and local income tax, but not FICA — and are clamped at the 2026 IRS limit ($4,400 self-only / $8,750 family, Rev. Proc. 2025-19). Age-55+ catch-up is not modeled. Payroll (Section 125) HSAs are also FICA-exempt in reality, so we slightly understate take-home for those users (conservative).
• Ohio school district income tax (SDIT) is never auto-applied from ZIP code alone. ZIP→school-district mapping requires Finder boundary data. User must confirm their district.
• Single filing status used for all precomputed SEO tables (see locality pages). Use the calculator for your actual status.

2. Federal tax

Income tax brackets & standard deduction

Source: IRS Rev. Proc. 2025-32. 2026 inflation-adjusted brackets. Standard deductions: $16,100 (single), $32,200 (married filing jointly), $24,150 (head of household).

3. FICA (Social Security & Medicare)

• Social Security: 6.2% on wages up to $184,500 (2026 wage base).
• Medicare: 1.45% on all wages (no ceiling).
• Additional Medicare: 0.9% on wages above $200,000 (single/HoH) or $250,000 (MFJ). Note: this threshold is not inflation-adjusted.
• Health premiums reduce FICA wages (Section 125 cafeteria plan). 401(k) contributions do NOT reduce FICA wages.

4. Local & state-level sources

Every jurisdiction carries a status: VERIFIED (official government publication only) or SECONDARY (aggregator or pending official source). The UI shows a BETA badge whenever any SECONDARY or approximate rule contributed to a result.