Alternative Minimum Tax Calculator (US)

This Alternative Minimum Tax calculator gives a simplified estimate of whether AMT may apply using AMTI, exemption, and tentative minimum tax logic.

AMT is a parallel tax system designed to limit the benefit of certain deductions and preferences. It can affect taxpayers with high income, incentive stock options, large deductions, or other AMT adjustment items.

If regular tax is $45,000 but the tentative minimum tax calculation produces $52,000, the simplified AMT difference would be $7,000.

The actual AMT calculation can be much more detailed, especially when stock options, preference items, and exemption phaseouts are involved.

Review AMT exposure before exercising incentive stock options, realizing large capital gains, or making major deduction decisions.

This calculator is only a planning aid. AMT is one of the areas where professional tax advice can be especially useful.

Use this AMT calculator for a simplified Alternative Minimum Tax comparison when you already have regular taxable income, regular tax owed, AMT adjustments or preference items, an AMT exemption, and a simplified AMT rate.

The component adds adjustments to regular taxable income to form a simplified AMTI figure, subtracts the exemption, applies the entered AMT rate, and compares tentative minimum tax with regular tax.

It does not complete Form 6251, calculate exemption phaseouts, determine ISO treatment, handle AMT credits, or model every preference item.

Use itemized vs standard deduction when the question is deduction choice, and federal income tax when regular federal tax needs its own estimate.

Label saved scenarios with the tax year, AMT exemption, AMT rate, and adjustment items used because those assumptions drive the result.

Entering total income as AMT adjustments. Adjustments and preference items are the extra AMT-specific amounts added to regular taxable income in this simplified model.

Treating the AMT exemption default as automatically current for the tax year being planned.

Assuming the filing-status selector calculates all exemption phaseouts and AMT brackets. The exemption and rate are manual inputs here.

Using this page for detailed ISO exercise planning without modelling bargain element, holding period, sale treatment, and AMT credit separately.

Treating the result as a filing number. It is an orientation estimate, not a Form 6251 replacement.

Example: enter $180,000 of regular taxable income, $32,000 of regular tax owed, $20,000 of AMT adjustments, an $85,700 exemption, and a 26% simplified AMT rate.

The calculator estimates simplified AMTI, subtracts the exemption, calculates tentative minimum tax, and shows any AMT owed above regular tax.

Change the adjustment amount separately from the exemption and rate so you can see which assumption is moving the estimate.

If AMT appears after changing one input, review the source of the adjustment rather than treating the whole tax return as the cause.

Use federal income tax to estimate regular federal tax before comparing it with simplified tentative minimum tax here.

Use itemized vs standard deduction if deduction choice is one of the planning questions feeding regular tax.

Use capital gains tax us separately for a sale gain before deciding whether that gain affects AMT inputs.

Use professional tax software or an adviser for ISO exercises, AMT credit carryforwards, phaseouts, and material filing decisions.

Check that regular tax owed is a tax number, not income.

Check whether the exemption and AMT rate match the tax year and filing status you are modelling.

Check whether credits, ISO records, preference items, and exemption phaseouts require a full AMT worksheet.

Rerun this AMT calculator when regular taxable income, regular tax, adjustments, exemption, filing status, or AMT rate changes.

Recheck before exercising incentive stock options, realizing large gains, or making deduction decisions that may create AMT adjustments.

If this estimate differs from tax software, trace regular tax, AMTI adjustments, exemption, phaseout treatment, and AMT credits separately.