acalculator

How much AMT will I owe?

Type your income, the state and local taxes you paid and your other itemized deductions, and any incentive stock option spread. The answer is the 2026 alternative minimum tax you would owe on top of the regular tax.

Your numbers

Alternative minimum tax
$17,840.00

With $300,000.00 of AMT income, your tentative minimum tax is $54,574.00 against $36,734.00 of regular tax, so you owe $17,840.00 of AMT.

Tentative minimum tax
$54,574.00
Regular income tax
$36,734.00
Total income tax
$54,574.00
AMT income (AMTI)
$300,000.00
AMT exemption
$90,100.00
AMT base
$209,900.00

Alternative minimum tax: $17,840.00. With $300,000.00 of AMT income, your tentative minimum tax is $54,574.00 against $36,734.00 of regular tax, so you owe $17,840.00 of AMT.

Alternative minimum tax by incentive stock option spread

The results are estimates for information only. They are not financial, tax, or legal advice. Check the numbers with your lender or a qualified professional before you decide. Terms of use

How to calculate

Estimates the 2026 alternative minimum tax: AMT income, the exemption and its phase-out, the 26% and 28% tentative minimum tax, and the AMT owed over the regular tax, with incentive stock options.

Example with the default inputs (Filing status Single, Income (AGI) $200,000.00, State and local taxes deducted $10,000.00, Other itemized deductions $5,000.00, Incentive stock option spread $100,000.00, Other AMT adjustments $0.00): With $300,000.00 of AMT income, your tentative minimum tax is $54,574.00 against $36,734.00 of regular tax, so you owe $17,840.00 of AMT.

Method: AMTI = AGI − other itemized deductions (when you itemize; the standard deduction and state and local taxes are not allowed) + ISO spread + other adjustments. Exemption = $90,100 single or head of household, $140,200 jointly, less 50% of AMTI over $500,000 ($1,000,000 jointly), not below 0. Base = AMTI − exemption. Tentative minimum tax = 26% × base, or 28% × base − $4,890 above $244,500. AMT = tentative minimum tax − regular tax, if positive.

  • An estimate for tax year 2026 (IRS Rev. Proc. 2025-32 and Form 6251), not tax advice.
  • All income is ordinary income: qualified dividends and long-term gains, which keep their 0%, 15%, and 20% rates under AMT, are not included. No credits, no AMT foreign tax credit, no minimum tax credit from earlier years.
  • Married filing separately is not covered: its phase-out has an extra AMTI add-on.
  • Other itemized deductions are within their own limits. The regular tax takes the larger of the standard deduction and the itemized deductions: state and local taxes up to the 2026 limit ($40,400, less 30% of AGI over $505,000, not below $10,000) plus the others, less the IRC 68 cut above the 37% bracket.

Machine-readable copies: Markdown, JSON.

Worked examples

Each example is checked against the calculator on every build.

  1. Filing status Single, Income (AGI) $150,000.00, State and local taxes deducted $10,000.00, Other itemized deductions $5,000.00, Incentive stock option spread $0.00, Other AMT adjustments $0.00 gives AMT income (AMTI) $150,000.00, AMT exemption $90,100.00, Tentative minimum tax $15,574.00, Regular income tax $24,734.00, Alternative minimum tax $0.00.Source: Rev. Proc. 2025-32 AMT exemption $90,100; Form 6251: standard deduction added back
  2. Filing status Single, Income (AGI) $200,000.00, State and local taxes deducted $10,000.00, Other itemized deductions $5,000.00, Incentive stock option spread $150,000.00, Other AMT adjustments $0.00 gives AMT income (AMTI) $350,000.00, Tentative minimum tax $67,882.00, Regular income tax $36,734.00, Alternative minimum tax $31,148.00.Source: Form 6251 line 7: 28% × 259,900 − 4,890 (2% of $244,500)
  3. Filing status Married filing jointly, Income (AGI) $600,000.00, State and local taxes deducted $40,000.00, Other itemized deductions $30,000.00, Incentive stock option spread $500,000.00, Other AMT adjustments $0.00 gives AMT income (AMTI) $1,070,000.00, AMT exemption $105,200.00, Tentative minimum tax $265,254.00, Regular income tax $132,873.50, Alternative minimum tax $132,380.50.Source: Rev. Proc. 2025-32: $140,200 less 50% of AMTI over $1,000,000; SALT limited to $11,900 (IRC 164(b)(7)) and added back (Form 6251 line 2a)
  4. Filing status Single, Income (AGI) $700,000.00, State and local taxes deducted $0.00, Other itemized deductions $0.00, Incentive stock option spread $0.00, Other AMT adjustments $0.00 gives AMT exemption $0.00, AMT income (AMTI) $700,000.00.Source: Rev. Proc. 2025-32: the single exemption is fully phased out at $680,200 of AMTI

How it works

  1. Regular tax: a 2026 Form 1040 with your AGI as ordinary income. The deduction is the larger of the standard deduction ($16,100 single, $32,200 jointly or surviving spouse, $24,150 head of household) and your itemized deductions. Itemized deductions = state and local taxes up to the 2026 limit (IRC 164(b)(7): $40,400, less 30% of AGI over $505,000, not below $10,000) + other itemized deductions, less the IRC 68 cut: 2/37 of the lesser of them and AGI over the start of the 37% bracket ($640,600 single and head of household, $768,700 jointly). Tax = the Tax Table below $100,000 of taxable income (the rate schedule at the middle of the $50 row, rounded to whole dollars), the rate schedule above.
  2. AMT income (Form 6251 lines 1 to 4): AGI − other itemized deductions (only if you itemize) + ISO spread + other adjustments. The standard deduction and state and local taxes are not subtracted; the itemized deduction limit of IRC 68 does not apply.
  3. Exemption = $90,100 (single, head of household) or $140,200 (jointly, surviving spouse), less 50% of AMT income over $500,000 or $1,000,000, not below 0.
  4. AMT base = AMT income − exemption, not below 0.
  5. Tentative minimum tax = 26% × base up to $244,500; above it, 28% × base − $4,890 (that is 2% of $244,500).
  6. AMT = tentative minimum tax − regular tax, if positive. Total income tax = regular tax + AMT.

When the data is out of date

The exemptions and the 28% breakpoint are indexed each year. After the 2026 filing season the page keeps using the 2026 amounts and says so above the result.

Worked examples by hand

Single, $150,000 of AGI, $10,000 of state taxes, $5,000 of other itemized deductions. Itemized $15,000 is less than $16,100, so the standard deduction: taxable income $133,900, regular tax 1,240 + 4,560 + 12,166 + 24% × 28,200 = $24,734. AMT income $150,000; base 150,000 − 90,100 = $59,900; tentative minimum tax 26% × 59,900 = $15,574. Less than the regular tax: no AMT.

The same, with $200,000 of AGI and a $150,000 ISO spread. Regular: taxable $183,900, tax 1,240 + 4,560 + 12,166 + 24% × 78,200 = $36,734. AMT income 200,000 + 150,000 = $350,000; base 350,000 − 90,100 = $259,900; tentative minimum tax 28% × 259,900 − 4,890 = $67,882. AMT = 67,882 − 36,734 = $31,148.

Married filing jointly, $600,000 of AGI, $40,000 of state taxes, $30,000 of other itemized deductions, a $500,000 ISO spread. Regular: the state tax limit is 40,400 − 30% × (600,000 − 505,000) = $11,900, so itemized deductions are 11,900 + 30,000 = $41,900 (no IRC 68 cut below $768,700); taxable 600,000 − 41,900 = $558,100, tax $132,873.50. AMT income 600,000 − 30,000 + 500,000 = $1,070,000. Exemption 140,200 − 50% × 70,000 = $105,200; base $964,800; tentative minimum tax 28% × 964,800 − 4,890 = $265,254. AMT = 265,254 − 132,873.50 = $132,380.50.

Other questions people ask

What is the AMT exemption for 2026?

$90,100 for single and head of household filers and $140,200 for married filing jointly and surviving spouses ($70,100 married filing separately). It falls by 50 cents for each dollar of AMT income over $500,000, or $1,000,000 jointly, so it is gone at $680,200 single and $1,280,400 jointly (IRS Rev. Proc. 2025-32).

What changed for the AMT in 2026?

The 2025 tax law (P.L. 119-21) set the phase-out thresholds at $500,000 and $1,000,000 for 2026, and the exemption now falls by 50 cents per dollar of AMT income over them instead of 25 cents. More high earners lose their exemption faster, so more of them can owe AMT.

What are the AMT rates?

26% on the first $244,500 of AMT income after the exemption ($122,250 married filing separately) and 28% above it. Long-term capital gains and qualified dividends keep their 0%, 15%, and 20% rates.

Why do incentive stock options trigger AMT?

When you exercise ISOs and keep the shares past the end of the year, the spread (the value at exercise minus the price you paid) is not regular income but is added to AMT income. A large spread can push the tentative minimum tax above your regular tax.

Which deductions are not allowed under the AMT?

The standard deduction and the deduction for state and local taxes. Mortgage interest on a home, gifts to charity, and medical costs over 7.5% of AGI are still allowed.

Can I get the AMT back later?

AMT caused by timing items such as ISO exercises can give a minimum tax credit (Form 8801) in later years when your regular tax is higher than your tentative minimum tax. This calculator does not figure that credit.