IRS Federal Income Tax Estimator (2026)

Estimator

What the estimator handles

Wages (your W-2 Box 1, already net of pre-tax 401(k)), net freelance/self-employment income plus the self-employment tax on it, interest, dividends, net capital gains or losses, net rental/royalty income, and other income. Everything is treated as ordinary income and run through the 2026 federal brackets after the standard deduction, with a flat credit for each dependent and credit for the federal tax you have already paid in. It returns your taxable income, federal income tax, self-employment tax, total liability, and either a refund or a balance due.

For 2026 the standard deduction is $16,100 single, $32,200 married filing jointly, and $24,150 head of household (IRS inflation adjustments for 2026). Because this is a fast estimator, it deliberately skips the parts of a real return that need judgment.

Assumptions baked into the math:

• Standard deduction is always applied (2026: $16,100 single / $32,200 MFJ / $24,150 HoH) — no itemizing.
• Dividends are taxed 100% as ordinary income (no qualified-dividend preferential rate).
• Capital gains are taxed as ordinary income; a net capital loss is capped at $3,000 per year against other income.
• Rental/royalty income is taxed as ordinary income; a net loss is capped at $25,000 per year.
• Other income is taxed as ordinary income.
• Wages are entered as W-2 Box 1, already reduced by your pre-tax 401(k), so there is no separate retirement adjustment.
• The dependent credit is a flat $2,200 per dependent — no age limit, no income phase-out, nonrefundable (it cannot reduce income tax below zero).
• Half of self-employment tax is deducted in arriving at AGI.
• 2026 federal brackets; filing status Single, MFJ, or HoH only.
• No NY State or NYC tax.

What it doesn’t handle

This estimator intentionally leaves out everything that needs a real preparer’s judgment: itemized deductions (it always takes the standard deduction); separate 401(k), HSA, and student-loan-interest adjustments (enter wages as W-2 Box 1, already net of pre-tax 401(k)); the preferential long-term capital gains and qualified-dividend rates (everything here is taxed as ordinary income); and the real Child Tax Credit rules — the under-17 requirement, the income phase-out, and the refundable Additional Child Tax Credit — which are replaced by the flat $2,200-per-dependent credit.

It also skips AMT (Alternative Minimum Tax), NIIT (the 3.8 percent tax on investment income — use the capital gains calculator for that), the Earned Income Tax Credit, education credits, the saver’s credit, energy credits, the QBI deduction for pass-through businesses, the foreign tax credit, and all state and local tax. The big one most NYC clients miss: state and local tax is roughly equal to federal at higher income levels, so for a full picture you need both sides.

Why W-4 withholding is almost always wrong

The W-4 redesign in 2020 was supposed to make withholding more accurate. For W-2 single filers with no other income and no deductions, it works. For couples where both spouses work, anyone with significant 1099 income on the side, or anyone with bonuses or RSUs, the W-4 either over-withholds (giving you a big refund) or under-withholds (giving you a bill in April). A refund or balance due over $2,000 either way means the W-4 needs adjustment.