Estimate federal and state estate tax exposure before you file, using the actual Form 706 tentative-tax-minus-credit method — not a simplified exemption subtraction.
Federal exemption verified against IRS Rev. Proc. 2025-32. State figures: CT, NY, and WA verified directly; other states use secondary summaries — see the confidence badge shown after you calculate. Full methodology.
The calculator follows the actual Form 706 structure rather than a simplified “subtract the exemption” shortcut. Your gross estate minus itemized deductions (debts, funeral and administration expenses, the marital deduction, and charitable bequests) gives the taxable estate. If the selected state has its own estate tax, that state tax is computed first and then deducted from the federal base (IRC §2058). Federal tax is the tentative tax — the 26 U.S.C. §2001(c) unified rate schedule applied to the full federal taxable estate, starting from $0 — minus the applicable credit under §2010, which is that same schedule applied to your applicable exclusion amount: the $15,000,000 basic exclusion for 2026 (verified against IRS Rev. Proc. 2025-32), plus any DSUE ported from a deceased spouse.
Worked example: a single decedent with an $18,000,000 taxable estate in 2026, in a state with no estate tax. The tentative tax on $18,000,000 is $345,800 (the statutory tax on the first $1,000,000) plus 40% of the remaining $17,000,000 — $7,145,800. The applicable credit is the tentative tax on the $15,000,000 exclusion: $345,800 plus 40% of $14,000,000 — $5,945,800. Federal estate tax owed: $7,145,800 − $5,945,800 = $1,200,000, exactly 40% of the $3,000,000 above the exclusion. The method matters: restarting the brackets on just the $3,000,000 excess would give $1,145,800, understating the tax by $54,200 — a real bug this calculator had and fixed (see the update history below).
Portability, dates, and what is deliberately not modeled: DSUE is not automatic — it requires a timely Form 706 election by the deceased spouse's executor, and the calculator caps any DSUE you enter at the basic exclusion for the year that spouse died (a 2019 death, for example, can leave at most $11,400,000 of DSUE, not today's $15,000,000). A pre-2026 date of death uses that year's historical exclusion; planning years beyond 2026 fall back to 2026 figures and are flagged as extrapolated. Lifetime adjusted taxable gifts and prior gift tax paid are disclosed but not folded into the math (§2001(b) adjusts both the tax base and the credit in a way not modeled here), so the federal figure likely understates liability when large lifetime gifts exist. New York's exemption cliff (N.Y. Tax Law §952) and Connecticut's flat 12% rate are modeled exactly; some other states' graduated schedules are approximated at their top rate above the exemption and flagged as estimates in the result. See the full methodology page for source-confidence levels by state.
Federal exemption verified against IRS Rev. Proc. 2025-32. State figures: CT, NY, and WA verified directly; other states use secondary summaries — see the confidence badge shown after you calculate.
See the full methodology page for how every calculator on this site is sourced and how confidence levels are assigned.
Limitations and disclaimer
DueMATH provides estimates for educational purposes only and is not tax, legal, or financial advice. Tax laws change frequently and every situation is different — confirm any number here with a licensed CPA, tax attorney, or your state's Department of Revenue before making a financial decision.
Only if you live in (or own real estate in) one of the roughly dozen states that levy their own separate estate tax — most states don't have one at all. Where a state estate tax does apply, it's charged in addition to federal estate tax, not instead of it, and state exemption thresholds are typically far lower than the federal $15,000,000 exemption — some states start taxing estates as small as $1,000,000–$2,000,000.
No, and the difference matters for who actually pays. Estate tax is owed by the estate itself, calculated on the total value of everything the deceased owned, and is paid before assets are distributed to heirs. Inheritance tax, where it exists, is owed by the person receiving the money or property, at a rate that usually depends on their relationship to the deceased. A handful of states have an inheritance tax instead of (or in Maryland's case, alongside) an estate tax — this calculator only covers estate tax.
Yes — the federal gift tax and estate tax share a single unified lifetime exemption, so large taxable gifts made during your life reduce the exclusion amount available to your estate at death (26 U.S.C. §2001(b)). This calculator's simplified formula doesn't model adjusted taxable gifts or gift tax already paid; if you've made significant lifetime gifts beyond the annual exclusion amount, have a CPA or estate attorney run the full calculation rather than relying on the estimate here.
The statutory bracket table technically runs from 18% up to 40%, but those lower brackets only apply to the first $1,000,000 of an estate's value above the exemption — and the federal exemption is $15,000,000 per person for 2026. In practice, almost every real taxable estate is well past that $1,000,000 mark, so nearly all of the tax owed is calculated at the flat 40% top rate; the lower brackets are legacy structure from before the exemption grew this large.
Generally no federal estate tax return is required if the gross estate is under the basic exclusion amount and no portability election is needed. The one major exception: if you're married and want to preserve your deceased spouse's unused exclusion for later use (portability), a complete, timely Form 706 must still be filed for their estate — even though no federal tax is owed — or that unused exclusion is permanently lost. State filing requirements are separate and often have much lower thresholds, so check your state's rules independently.
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