Data sources
The calculator engines run on versioned tax-year data files. Each value carries an inline citation to its source:
- IRS Revenue Procedure 2025-32 — 2026 inflation adjustments (brackets, standard deduction, AMT, capital gains)(opens in a new tab)
- IRS Revenue Procedure 2024-40 — 2025 inflation adjustments(opens in a new tab)
- One Big Beautiful Bill Act (P.L. 119-21) — permanent TCJA rates, QBI, SALT cap, bonus depreciation(opens in a new tab)
- IRS Notice 2025-67 — 2026 retirement plan limits(opens in a new tab)
- SSA 2026 Fact Sheet — Social Security wage base ($184,500)(opens in a new tab)
- IRS Publication 946 — depreciation (MACRS tables)(opens in a new tab)
- IRS Publication 505 — withholding and estimated tax (safe harbor rules)(opens in a new tab)
Update policy
When tax law changes, the engines change. After the One Big Beautiful Bill Act (July 2025) repealed the scheduled TCJA sunset, every affected calculator was rebuilt on the permanent-law values: brackets, QBI, the expanded SALT cap and its 2030 reversion, 100% bonus depreciation and the new AMT phase-out rules.
Annual IRS inflation adjustments are applied when the Revenue Procedure for the year is published each fall.
Accuracy and limits
The calculation engines are covered by more than 350 automated tests, checked against IRS publication examples.
The calculators produce planning estimates, not tax advice. They simplify items such as multi-state income, credits and unusual situations. For a decision with real money attached, Krystal checks your numbers on a call.