Alternative Minimum Tax (AMT) Calculator
Find out whether the Alternative Minimum Tax applies to you and how much extra you owe. Enter your regular taxable income, any AMT preference items (such as exercised incentive stock options or state-tax deductions), your filing status, and your regular computed tax — the calculator does the rest.
Filing status
$
$
$
$
$
$
Additional tax above your regular income tax — zero means AMT does not apply
- 1
Alternative Minimum Taxable Income (AMTI)
300,000 + 50,000 = 350,000 - 2
Effective AMT exemption
85,700 − 25% × max(0, 350,000 − 609,350) = 85,700The exemption is reduced by $0.25 for every $1 of AMTI above the phase-out threshold. - 3
AMT base
max(0, 350,000 − 85,700) = 264,300 - 4
Tentative minimum tax (TMT)
26% × 220,700 + 28% × 43,600 = 69,590 - 5
AMT owed
max(0, 69,590 − 55,000) = 14,590
How does this calculator work?
AMT adds back certain deductions to create AMTI, subtracts an inflation-adjusted exemption (that phases out at high incomes), applies a 26%/28% rate to get the Tentative Minimum Tax, and you pay whichever is higher — regular tax or TMT. In 2024, the AMT exemption is $85,700 for single filers, phasing out above $609,350.
Formula
How this is calculated
The Alternative Minimum Tax is a parallel US federal tax system designed to ensure that high-income taxpayers pay at least a minimum amount of tax, regardless of deductions and credits. It works by computing your income under a stricter set of rules — adding back "preference" items such as the spread on exercised incentive stock options (ISOs), accelerated depreciation, and certain itemised deductions — to arrive at Alternative Minimum Taxable Income (AMTI).
From AMTI you subtract an exemption amount that phases out at 25 cents per dollar of AMTI above a threshold ($609,350 for single filers in 2024). The remaining AMT base is taxed at 26% on the first $220,700 and 28% above that (or $110,350 / $110,350 for Married Filing Separately). This produces the Tentative Minimum Tax (TMT). You pay AMT only if TMT exceeds your regular income tax.
The 2024 figures used here (IRS Rev. Proc. 2023-34) are editable via the override fields — useful for 2025 filing once IRS inflation-adjusts the numbers. This calculator is for estimation; state AMT, foreign tax credits, and AMT credit carryforwards are not modelled. Consult a tax professional for your actual liability.
Frequently asked questions
Common triggers include exercising incentive stock options (ISOs), large state and local tax (SALT) deductions, accelerated depreciation on property, and high overall income. If your AMTI exceeds the exemption and results in a Tentative Minimum Tax above your regular tax, AMT applies.
For every dollar your AMTI exceeds the phase-out threshold ($609,350 single / $1,218,700 MFJ in 2024), the exemption is reduced by 25 cents. Once AMTI is far enough above the threshold, the exemption is fully eliminated.
Yes. If you pay AMT in a given year because of deferral items (such as ISO exercises that later become regular income), you can carry forward an AMT credit (Form 8801) to offset regular tax in future years when you are not subject to AMT.
TG we-Calculate Editorial Team. (2026). Alternative Minimum Tax (AMT) Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/alternative-minimum-tax-calculator
TG we-Calculate Editorial Team. "Alternative Minimum Tax (AMT) Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/alternative-minimum-tax-calculator.
TG we-Calculate Editorial Team, "Alternative Minimum Tax (AMT) Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/alternative-minimum-tax-calculator
@misc{wecalculate_alternative_minimum_tax_calculator, title = {Alternative Minimum Tax (AMT) Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/alternative-minimum-tax-calculator}}, year = {2026}, note = {TG we-Calculate} }
Did this calculator help you?