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AMT (Alternative Minimum Tax) Calculator

Estimate tentative AMT using 2024 exemption amounts and see if you owe AMT above your regular tax.

Results

AMT exemption: $85,700 USD
AMT taxable income: $114,300 USD
Tentative minimum tax: $29,718 USD
AMT owed (if any): $0 USD

How to use this calculator

Choose your filing status.
Enter AMTI before the exemption (after adding back AMT preference items) and your regular tax from Form 1040.
We apply the 2024 exemption and phaseout, compute tentative AMT at 26%/28%, and show any AMT owed above your regular tax.

Inputs explained

AMT income before exemption: AMTI before applying the AMT exemption. Add back AMT adjustments first.
Regular tax: Your regular tax liability before AMT. Used to see if tentative AMT exceeds it.
Filing status: Determines exemption amount, phaseout threshold, and the 26/28% breakpoint.

How it works

We start with AMT income (AMTI) before the exemption and apply the 2024 exemption for your filing status.

If AMTI exceeds the phaseout threshold, the exemption is reduced by 25% of the excess until it phases out.

Tentative minimum tax = 26% of AMT taxable income up to the 26/28% breakpoint, then 28% above it.

AMT owed = max(tentative minimum tax − regular tax, 0).

Formula

Exemption = Max(0, Base exemption − 25% × max(0, AMTI before exemption − Phaseout threshold))
Taxable AMTI = AMTI before exemption − Exemption
Tentative minimum tax = 26% of taxable AMTI up to breakpoint + 28% above it
AMT owed = Max(tentative minimum tax − regular tax, 0)

When to use it

Checking if incentive stock option exercises or large deductions trigger AMT.
Comparing AMT exposure across filing statuses and income scenarios.
Quickly estimating AMT before year-end planning or tax prep.

Tips & cautions

Update inputs annually—exemptions and phaseout thresholds change each tax year.
Large ISO exercises often create AMT income; include the bargain element in AMTI for a realistic check.
State taxes, miscellaneous deductions, and private-activity bond interest can increase AMTI.
Uses 2024 AMT exemption/phaseout thresholds and the standard 26%/28% rates.
Does not include AMT foreign tax credits or other AMT credits.
Simplifies AMTI entry—ensure you add back preference items before using this estimator.

Worked examples

MFJ, AMTI before exemption $400,000, regular tax $60,000

Exemption ≈ $133,300; Taxable AMTI ≈ $266,700
Tentative minimum tax ≈ $70,024
AMT owed ≈ $10,024 after subtracting regular tax

Deep dive

Estimate alternative minimum tax with 2024 exemptions, phaseout, and 26%/28% brackets to see if you owe AMT above your regular tax.

Enter AMTI before the exemption and your regular tax to calculate the tentative minimum tax and any AMT owed.

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Simplified AMT estimator using 2024 thresholds; not tax advice. Verify with IRS worksheets or a tax professional for your situation.