AMT Calculator

Impacts exemption/phaseout.

Before prefs; high AGI triggers.

Added back for AMT.

Common pref; added back.

FMV - exercise; big AMT trigger.

Depreciation diff, interest, etc.

From income tax calc; AMT excess over this.

AMT Calculator: Avoid 2025 Alternative Minimum Tax Surprises

High earners: Use our AMT Calculator to estimate parallel tax liability. For 2025, adds back prefs (state taxes, ISO, misc), subtracts exemption (phaseout >$100k+), applies 26/28% rates. Outputs tentative minimum; pay excess over regular. Guide details triggers, Form 6251, planning (defer ISO), credits. Complements Income Tax Calculator.

What is AMT?

Parallel system ensures min tax for high-income with prefs. No std deduction, limited credits. Our AMT Calculator approximates Form 6251.

Why Calculate AMT?

Reasons:

  • Avoid Underpayment: Penalties.
  • ISO Planning: Exercise timing.
  • High Deductions: State taxes, misc.
  • Credit Use: AMT credits later.

Link to Withholding Calculator.

Calculation Steps: 2025 Rules

Process:

  1. AMTI: AGI + prefs - some.
  2. Exemption: $85,700 single (phaseout 25% over threshold).
  4. Tentative AMT: 26% to $232,600, 28% over.
  5. AMT: Tentative - regular (if positive).

Example: $250k AGI single, $20k state, $50k ISO: AMTI ~$300k; tentative ~$70k; if regular $50k → $20k AMT.

2025 Exemptions & Rates

Exemption: $85,700 single/$171,400 joint. Phaseout: $609,350 single/$1,218,700 joint start, full at higher. Rates: 26/28%.

Common Triggers

ISO, high state taxes, accel dep, tax-exempt interest.

Strategies to Avoid AMT

Tips:

  • Defer ISO: Low AMT year.
  • Bunch Deductions: Alternate years.
  • Prepay Property Tax: If not triggering.
  • Use Credits: Generate AMT credit.

Use Charitable Deduction Calculator (deductible both).

AMT vs Regular Tax

Pay higher; AMT often for $150k-$500k with prefs.

Form 6251 & Credits

File if triggered; prior AMT → credit Form 8801.

Common Errors

Avoid:

  • Forgetting Phaseout: Reduces exemption.
  • Missing Prefs: Underestimate AMTI.
  • No Regular Tax Input: Wrong liability.
  • Ignoring Credits: Overpay.

High Earners & ISO

Biggest trigger; plan exercises.

Conclusion

Stay ahead with our AMT Calculator—2025-accurate estimates prevent owes. Adjust W-4, plan prefs. Explore Tax Refund Calculator. Compute now!

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