Estate Tax Calculator

Estimate US federal estate tax based on your gross estate, deductions, marital situation (including portability/DSUE), and prior taxable gifts, with an optional state estate or inheritance tax estimate. You will also see a clear breakdown of what amount is being taxed and why.

How to use our Estate Tax Calculator

1. Select the tax year you want to estimate (usually the year of death).
2. Choose your situation (Single or Married with portability) so the calculator knows whether to include DSUE.
3. Enter the gross estate value (USD), meaning the total value of assets counted for federal estate tax (not just probate assets).
4. Enter deductions (USD) such as debts, administration expenses, charitable bequests, and marital deduction amounts (use 0 if unknown to see an upper-bound).
5. Enter adjusted taxable gifts (USD) from lifetime gifts that used lifetime exclusion (not annual-exclusion gifts).
6. Open Advanced options if you need to override the federal exclusion, enter DSUE, or enter gift taxes already paid.
7. If you want a rough state estimate, set Include state estimate to Yes, then choose a state and tax type and enter a state exemption and top rate percent.
8. Click Calculate and review the outputs and any notes or warnings (especially about missing state inputs or cliff rule risk).

Definitions

Gross estate value: The total value of assets that can be counted for federal estate tax, including some items that may not go through probate (for example, some jointly held property or certain life insurance situations).[1]

Deductions: Amounts that reduce what is taxed, such as debts, administration expenses, charitable bequests, and marital deduction amounts.[1]

Taxable estate: Gross estate minus deductions (floored at 0 in this calculator so you do not get negative tax bases).[1]

Adjusted taxable gifts: Lifetime taxable gifts that used up lifetime exclusion; this is not the same as gifts covered by the annual exclusion.[1]

Federal exclusion (basic exclusion amount): The lifetime amount that can be transferred before federal estate tax is estimated to apply; this tool defaults to a 2026 value unless you override it.[4]

DSUE (deceased spouse unused exclusion): Extra exclusion a surviving spouse may be able to use if a portability election was (or will be) made on a timely estate tax return.[1]

Estate tax vs inheritance tax: An estate tax is charged to the estate; an inheritance tax is charged to the person receiving the inheritance (rules vary by state).[3]

Cliff rule (state): A state feature where going slightly over the exemption can make much more (or all) of the estate taxable; this calculator can only show a simplified warning and estimate.

Methodology

What this calculator is doing

This is a planning estimate for US federal estate tax and an optional, user-parameterized state estimate. Federal estate tax is generally reported on Form 706 and is typically paid by the estate.[2]

Step 1: Compute taxable estate

taxable_estate = max(0, gross_estate_value - deductions_total)

If deductions are unknown, leaving them at 0 shows a higher (upper-bound) taxable estate than you might have after real deductions.[1]

Step 2: Determine total exclusion available

exclusion_used = (federal_exclusion_override if provided else federal_exclusion_by_year) + dsue_amount

The default federal exclusion for 2026 is set to 15000000 USD based on the cited reference.[4] DSUE is only meant to be used when portability applies; the DSUE input is hidden when you select Single.[1]

Step 3: Calculate the amount over the exclusion (simplified)

amount_over_exclusion = max(0, (taxable_estate + adjusted_taxable_gifts) - exclusion_used)

This shows how lifetime taxable gifts can reduce the remaining exclusion available at death. Actual federal computations can be more detailed than this simplified view.[1]

Step 4: Estimate federal estate tax using a simplified top-rate method

estimated_federal_estate_tax = amount_over_exclusion * top_rate

The top_rate used here is 0.40 (40%). This tool uses that as a simple, stable estimate rather than implementing the full bracket table.[1]

Step 5: Subtract prior gift tax paid (simplified adjustment)

estimated_federal_estate_tax_after_gift_tax_paid = max(0, estimated_federal_estate_tax - gift_taxes_paid)

If gift taxes paid are larger than this estimate, the output floors at 0. Any extra amount is not treated as a refund in this simplified model.

Optional: State estate or inheritance tax estimate (user inputs)

If include_state_tax=No: state_tax = 0

If include_state_tax=Yes and state_exemption_amount is blank: state_tax = N/A

Else: state_taxable = max(0, taxable_estate - state_exemption_amount)

If state_cliff_rule=Yes and taxable_estate > state_exemption_amount: state_taxable_cliff = taxable_estate

state_tax = (state_taxable or state_taxable_cliff) * (state_top_rate_percent/100)

State rules vary a lot, and some states have estate taxes and/or inheritance taxes with changing exemptions and rates.[3] Because of that, this tool does not hardcode state law. You provide the exemption and top rate you want to model. If you turn on the cliff rule, the calculator also shows a simplified cliff-style estimate and a warning when you are close to the exemption.

Total tax

estimated_total_tax = estimated_federal_estate_tax_after_gift_tax_paid + estimated_state_tax

If the state estimate is N/A, the total will also be shown as N/A so you do not accidentally treat it as a complete total.

Input validation and edge-case handling

USD inputs must be valid numbers. Gross estate must be 0 or more. Deductions, adjusted taxable gifts, DSUE, and gift taxes paid cannot be negative. When a state estimate is enabled, state top rate percent is required (blank is an error). If the federal exclusion override is entered, it must be a positive number. Notes and warnings appear only when relevant (example: missing state exemption, cliff risk, or gift tax paid exceeding the estimate).

Sources