How to Use the Estate Tax Calculator (Worked Examples)
Six worked estate tax scenarios with real math: estates under the exemption, portability, the 40 percent rate, state taxes on modest estates, charity, and lifetime gifts.
Reading estate tax rules is one thing; watching them produce a number is another. This companion to our estate tax calculator (/estate-tax-calculator.html) works six realistic scenarios end to end with published 2025 parameters: the 13.99-million-dollar per-person exemption, the graduated rate table rising to 40 percent, and the portability election. Every figure can be checked by hand against the Form 706 tax schedule, and the same logic carries into 2026, where legislation enacted in July 2025 raises the basic exclusion to 15 million dollars per person. Treat each result as an educational estimate for planning conversations — not a filed return, and not a substitute for an estate attorney or CPA reviewing the actual documents.
CHAPTER 01Before You Start: The Inputs That Drive Everything
Five inputs decide almost everything: the gross estate at date-of-death value (not purchase price), debts and administrative costs, charitable and marital bequests, prior taxable gifts beyond the annual exclusion, and the state of residence. The tax runs on the taxable estate — gross value minus deductions — compared against the exemption, with the graduated 18-to-40-percent schedule applied to the excess.
Two habits make every scenario below accurate. First, value assets as of the date of death, not the date of planning; markets move. Second, count the life insurance the decedent owned, because it enters the gross estate even though nobody files it as a house would. If the calculator asks for a state, answer honestly — the state layer is where mid-size estates get surprised.
CHAPTER 02Scenario 1 — A Single Decedent Comfortably Under the Exemption
A widower dies in 2025 leaving a 6.2-million-dollar gross estate: a paid-off house, brokerage accounts, and a car. Debts and final expenses total 200,000 dollars, so the taxable estate is 6 million. Against the 13.99-million-dollar exemption the excess is zero, and the calculator returns 0 dollars of federal estate tax. No Form 706 is federally required for him, and the executor's remaining duty is documenting the date-of-death values that made the answer obvious.
The honest caveats: his state may disagree. A Massachusetts resident with this estate crossed the 2-million-dollar state threshold for 2025, and an Oregon resident crossed theirs at 1 million. And because he is single, portability — the reason many no-tax estates file anyway — does not apply. The federal answer is genuinely zero; the state answer depends on where he lived.
CHAPTER 03Scenario 2 — Portability on an Estate That Owes Nothing
A first spouse dies in 2025 with an 8-million-dollar estate and leaves everything to the surviving spouse. The unlimited marital deduction wipes out the taxable base, so the federal tax is 0 dollars — but the executor wisely files Form 706 anyway, electing portability. The surviving spouse's DSUE amount becomes the full 13.99 million dollars, because none of the first spouse's exemption was used.
Years later the survivor dies in 2026 with a 26-million-dollar estate. Her own exclusion is 15 million, and the DSUE adds 13.99 million, for 28.99 million total — the excess is zero and the tax is 0 dollars. Without the portability election, the excess would have been 11 million dollars, producing 345,800 plus 40 percent of 10 million, or about 4,346,000 dollars. One timely filing, made when no tax was due, saved roughly 4.3 million.
CHAPTER 04Scenario 3 — Crossing the Line: the 40 Percent Rate at Work
A single decedent in 2025 leaves a taxable estate of 16.49 million dollars. The excess over the 13.99-million-dollar exemption is 2.5 million dollars, and the schedule applies: 345,800 dollars of tentative tax at the one-million mark, plus 40 percent of the remaining 1.5 million, for a total of 945,800 dollars — about 946,000, payable on the IRS schedule in cash the estate may not have on hand.
Notice what the headline rate does and does not mean. The 40 percent applies only to the excess, so the effective rate on the whole estate here is under 6 percent. Executors who assume the entire estate is taxed at 40 percent panic; planners who know the structure negotiate calmly. The calculator makes the distinction automatic instead of arithmetic, and it shows how a charitable bequest or a state move would change the excess the 40 percent actually lands on.
CHAPTER 05Scenario 4 — The State Tax on a Modest Estate
A Massachusetts resident dies in 2025 with a taxable estate of 3.4 million dollars — a house bought decades ago plus retirement accounts. The federal calculation returns zero: 3.4 million sits far below 13.99 million. But Massachusetts taxed estates above 2 million dollars for 2025, and our estate tax calculator (/estate-tax-calculator.html), loaded with the state schedule, returns a bill on the order of 100,000 dollars, due on the state's own deadline.
The lesson is structural, not numeric. For estates between roughly 1 and 14 million dollars, the binding constraint is usually the state, not the federal government — Oregon's 1-million-dollar threshold for 2025 is the lowest, with Massachusetts, Washington, and Minnesota not far behind. A calculator that stops at the federal line understates the real bill for exactly the families most likely to use it.
CHAPTER 06Scenario 5 — Charity Rewrites the Bill
A decedent leaves a 15.2-million-dollar taxable estate in 2025 with no spouse and no prior gifts. The excess over 13.99 million is 1.21 million dollars, taxed at 345,800 plus 40 percent of 210,000 — about 429,800 dollars. Her will then directs 1.5 million to a charitable foundation, and the unlimited charitable deduction applies: the taxable estate falls to 13.7 million, below the exemption, and the federal bill drops to 0 dollars.
Read the trade honestly. Heirs previously would have netted about 14.77 million after tax; with the bequest they net 13.7 million — 1.07 million less, not 1.5 million less, because the gift eliminated 429,800 of tax on the way. Charitable bequests are among the few levers that change the estate tax arithmetic this directly, and the calculator prices each version in one pass.
CHAPTER 07Scenario 6 — Lifetime Gifts Come Home to Roost
A decedent gave away 4 million dollars of reportable taxable gifts over her lifetime — amounts beyond the 19,000-dollar annual exclusions — all properly reported on Form 709. Her 2025 taxable estate is 14.5 million dollars. The gifts consumed 4 million of exemption, leaving 9.99 million; the excess is 4.51 million, and the tax is 345,800 plus 40 percent of 3.51 million, about 1,749,800 dollars.
Compare the no-gift world: the same estate would have exceeded the full 13.99-million exemption by only 510,000, producing roughly 158,500 dollars of tax. The gifts themselves were tax-free when made, but they moved exemption forward — and carried the donor's income-tax basis out of the estate, which our gift tax calculator (/gift-tax-calculator.html) treats in detail. Gifting is a strategy with three ledgers: gift tax now, estate tax later, and capital gains in between.
CHAPTER 08What a Calculator Cannot Model
Every scenario above used clean, appraised-at-market inputs. Real estates involve closely held businesses with valuation discounts, fractional interests, pending lawsuits, caretaker arrangements, and family loans that may or may not be treated as gifts. Audits of large estates are a real event, and valuation is the battleground. None of that fits in an input box, which is why these six scenarios end exactly where an attorney's file begins.
Use the worked numbers here to understand the mechanics — the exemption line, the 40 percent excess, the portability election, the state threshold — and then hand the actual estate to a professional with the calculator's first draft attached. Figures cited are published 2025 parameters, hedged accordingly, and 2026 brings a 15-million-dollar exclusion that will change several of these answers.
🔑 Key takeaways
- A 6-million-dollar estate owes 0 federal tax under the 13.99-million-dollar 2025 exemption — but Massachusetts or Oregon may tax it anyway.
- Portability preserved 13.99 million of DSUE on a no-tax estate and later erased a 4.35-million-dollar bill for the survivor.
- The 40 percent rate applies only to the excess over the exemption — one 16.49-million-dollar estate owed 946,000, under 6 percent effective.
- A 1.5-million-dollar charitable bequest wiped out a 429,800-dollar federal bill, costing heirs 1.07 million net rather than the full gift.
- 4 million dollars of lifetime gifts raised one estate's bill from about 158,500 to 1.75 million — exemption is a single shared bucket.
- Every result is an educational estimate on your inputs; valuations, audits, and state schedules are professional territory.
❓ Frequently asked questions
Does an estate under the federal exemption still file Form 706?
Sometimes. Portability for a surviving spouse requires it, some states require a separate filing at their lower thresholds, and certain elections and basis documentation make it wise. A purely federal, under-exemption, single-decedent estate generally does not file.
What if we already missed the portability deadline?
Ask about the simplified late election: estates not otherwise required to file Form 706 can generally elect portability within about five years of death under IRS guidance. Estates that had to file for other reasons have less relief — a professional should review the facts.
Is the 40 percent rate charged on the whole estate?
No. The graduated schedule runs from 18 to 40 percent, and the top rate applies only to the excess over the exemption. Effective rates on entire taxable estates are typically a fraction of the headline number.
Do retirement accounts count toward the estate?
Yes, at date-of-death value — IRAs and 401(k)s are estate assets even though they also carry income tax when beneficiaries withdraw them, under income-in-respect rules. The two layers are why retirement-heavy estates need careful modeling.
Does the estate tax apply to noncitizens?
US residents and citizens use the full worldwide computation with the 13.99-million-dollar 2025 exemption. Nonresident aliens face tax only on US-situs assets, but with a tiny 60,000-dollar exemption for 2025 — a genuinely professional-territory area.
How does the calculator treat a revocable living trust?
Assets in a revocable trust are part of the gross estate exactly as if owned personally — these trusts avoid probate, not estate tax. Enter them as regular assets; assuming trust labels change the tax is one of the field's classic errors.
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