# AMT Calculator – Alternative Minimum Tax

URL: https://speedycalculator.com/calculators/finance/amt/
Last updated: 2026-10-25

> The AMT calculator estimates whether you owe the alternative minimum tax for 2026: it adds back preference items to taxable income, subtracts the AMT exemption (reduced above the phase-out threshold), applies the 26% and 28% rates and compares the result with your regular tax.

## Inputs

- Filing status
- Regular taxable income
- State and local taxes deducted (add-back)
- Other AMT adjustments (ISO spread, private bond interest)
- Regular federal income tax (leave 0 to estimate)

## Results

- Alternative minimum taxable income (AMTI)
- AMT exemption after phase-out
- AMT base
- Tentative minimum tax
- Regular tax used
- Alternative minimum tax owed

## Formula

```
AMTI = taxable income + state and local taxes deducted + other preference items
Exemption 2026: $90,100 single / $140,200 joint, reduced by 50% of AMTI above $500,000 / $1,000,000
Tentative minimum tax = 26% up to $244,500 (+28% above) of AMTI − exemption
AMT = max(TMT − regular tax, 0)
```

## Explanation

The AMT is a parallel tax system that makes sure high earners with many deductions pay a minimum tax. Since 2018 far fewer people owe it, but exercising incentive stock options or large state tax deductions can still trigger it.

### How to use the AMT Calculator – Alternative Minimum Tax

- **Filing status**
- **Regular taxable income**
- **State and local taxes deducted (add-back)**
- **Other AMT adjustments (ISO spread, private bond interest)**
- **Regular federal income tax (leave 0 to estimate)**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter your filing status, regular taxable income, regular federal tax, state and local taxes you deducted, and other AMT preference items (such as ISO bargain element).

### Tips

- Tax figures here are estimates for planning – your actual tax depends on credits, deductions and local rules.
- Check the tax year and filing status before you rely on a result.
- Use gross (before-tax) figures unless a field asks for take-home pay.
- When in doubt, confirm with the tax authority's own calculator or a tax professional.

### Common mistakes to avoid

- Confusing marginal and effective tax rates.
- Adding sales tax to a price that already includes it.
- Forgetting payroll taxes (Social Security and Medicare) on wages.

### Inputs explained

FieldWhat to enterFiling statusChoose one: Single, Married filing jointly, Married filing separately, Head of householdRegular taxable incomeAmount in your currencyState and local taxes deducted (add-back)Amount in your currencyOther AMT adjustments (ISO spread, private bond interest)Amount in your currencyRegular federal income tax (leave 0 to estimate)Amount in your currency

### What each result means

- **Alternative minimum taxable income (AMTI)** = [Regular taxable income] + [State and local taxes deducted (add-back)] + [Other AMT adjustments (ISO spread, private bond interest)]
- **AMT base** = max([Alternative minimum taxable income (AMTI)] - [AMT exemption after phase-out], 0)
- **Alternative minimum tax owed** = max([Tentative minimum tax] - [Regular tax used], 0)

### Example values

How the main result changes when **Regular taxable income** changes and everything else stays at the example values above:

Regular taxable incomeAlternative minimum tax owed160,00013,176240,00011,826320,0006,712.75400,0001,112.75480,0006,712.75640,0009,540.75

## Worked example

Inputs — Filing status: Single; Regular taxable income: $320,000; State and local taxes deducted (add-back): $40,000; Other AMT adjustments (ISO spread, private bond interest): $60,000; Regular federal income tax (leave 0 to estimate): $0.

Results — Alternative minimum taxable income (AMTI) = $420,000.00; AMT exemption after phase-out = $90,100.00; AMT base = $329,900.00; Tentative minimum tax = $87,482.00; Regular tax used = $80,769.25; **Alternative minimum tax owed = $6,712.75**.

## FAQ

**Who pays the AMT?**
Mostly high earners with large preference items such as incentive stock options.

**What are the 2026 AMT exemptions?**
$90,100 for single filers and $140,200 for married couples filing jointly.

**How is AMT different from regular tax?**
It disallows some deductions, then applies 26% and 28% rates.

**What formula does the AMT Calculator – Alternative Minimum Tax use?**
AMTI = taxable income + state and local taxes deducted + other preference items.


## Sources

- [IRS – Tax inflation adjustments for tax year 2026](https://www.irs.gov/newsroom/irs-releases-tax-inflation-adjustments-for-tax-year-2026-including-amendments-from-the-one-big-beautiful-bill)