Alternative Minimum Tax (AMT) Calculator (US)
Calculate US Alternative Minimum Tax (AMT) with 2024 exemptions, 26%/28% brackets, and phaseout rules. Online tool for AGI, filing status, and tax credits.
About This Calculator
The Alternative Minimum Tax (AMT) is a supplemental US federal tax system designed to ensure that high-income taxpayers pay at least a minimum amount of tax. Unlike the regular income tax system, AMT disallows certain deductions such as state and local taxes, miscellaneous itemized deductions, and personal exemptions. Taxpayers must compute their liability under both systems and pay whichever is higher.
This calculator implements the official IRS AMT rules for the 2024 tax year. It computes your Alternative Minimum Taxable Income (AMTI) by adding back non-deductible taxes to your Adjusted Gross Income, applies the appropriate exemption based on your filing status (with phaseout adjustments), and calculates tax using the two-tier 26%/28% rate structure minus any applicable tax credits.
Regional Notes
United States: The AMT applies at the federal level under IRS rules. Exemption amounts, phaseout thresholds, and rate limits are indexed annually for inflation. The Tax Cuts and Jobs Act (TCJA) significantly reduced AMT applicability by increasing exemption amounts and phaseout thresholds.
India: India has a similar concept called Minimum Alternate Tax (MAT) under Section 115JB for companies, calculated at 15% of book profits. This calculator focuses on the US individual AMT system.
United Kingdom: The UK does not have a direct equivalent to the US AMT. However, the High Income Child Benefit Charge and the tapered personal allowance for incomes above £100,000 serve similar functions of recapturing tax benefits at higher income levels.
Formula
AMTI = AGI + Non-Deductible Taxes
Exemption = Base Exemption - max(0, AMTI - Phaseout Threshold) x 0.25
Taxable AMT = max(0, AMTI - Exemption)
AMT = (min(Taxable AMT, 26% Limit) x 26%) + (max(0, Taxable AMT - 26% Limit) x 28%) - Tax Credits
Frequently Asked Questions
What is the Alternative Minimum Tax (AMT)?
The Alternative Minimum Tax (AMT) is a parallel US tax system that ensures high-income taxpayers pay a minimum amount of tax. Taxpayers must calculate their tax under both the regular system and the AMT system, then pay the higher amount. The AMT disallows certain deductions like state and local taxes and applies a two-tier rate structure of 26% and 28%.
How do you calculate the Alternative Minimum Tax?
To calculate AMT, start with your Adjusted Gross Income (AGI) and add back non-deductible taxes to get Alternative Minimum Taxable Income (AMTI). Subtract the applicable AMT exemption amount (which phases out at higher income levels) to get your taxable AMT. Apply the 26% rate to income up to the threshold and 28% to any excess. Finally, subtract any allowable tax credits. You owe the higher of your regular tax or AMT.
What are the AMT exemption amounts for 2024?
For the 2024 tax year, the AMT exemption is $85,700 for married couples filing jointly (phaseout begins at $609,350), $66,000 for single filers (phaseout at $529,300), and $42,850 for married filing separately (phaseout at $304,675). The exemption reduces by 25 cents for every dollar of AMTI above the phaseout threshold.
What deductions are disallowed under the AMT?
Under the AMT system, several deductions allowed under regular tax rules are disallowed. These include state and local tax deductions, miscellaneous itemized deductions, and personal exemptions. The standard deduction is also not allowed under AMT. This means taxpayers with large state and local tax deductions or high miscellaneous expenses are most likely to owe AMT.
Who is most likely to be subject to the AMT?
Taxpayers most likely to be affected by AMT are those with high incomes who claim significant deductions, particularly state and local taxes (SALT), large families with multiple personal exemptions, taxpayers who exercise incentive stock options (ISOs), and those with substantial investment expenses or miscellaneous itemized deductions.
Is this calculator free to use?
Yes, this Alternative Minimum Tax calculator is completely free to use with no registration required. The URL saves your inputs automatically so you can bookmark or share your exact calculation with others.
What is the difference between the 26% and 28% AMT rates?
The AMT uses a two-tier rate structure. For 2024, single and married joint filers pay 26% on the first $232,600 of taxable AMT and 28% on any excess above that amount. Married filing separately filers pay 26% on the first $116,300 and 28% on the excess. These thresholds are indexed for inflation each year.
How can I reduce my AMT liability?
Strategies to reduce AMT liability include deferring the exercise of incentive stock options (ISOs), avoiding high state and local tax deductions in high-income years, accelerating or deferring income to stay below phaseout thresholds, and maximizing tax credits like the Child Tax Credit. Consulting with a tax professional is recommended for personalized AMT planning.