The headline number is simple — $15,000,000 per person. The part that goes wrong by hand is portability, the GST trap, and whether last year's "sunset" warning still applies (it does not).
| Step | Common mistake by hand | What this calculator does |
|---|---|---|
| Married exclusion | Assumes marriage automatically doubles the exclusion to $30,000,000. | Only adds a second $15,000,000 if a DSUE amount from an actual portability election is entered. |
| GST exemption | Assumes the GST exemption is portable between spouses like the estate/gift exclusion. | Flags explicitly that the GST exemption has never been portable, even though it shares the same $15,000,000 figure. |
| Prior gifts | Treats lifetime gifts and the estate exclusion as two separate buckets. | Subtracts prior taxable gifts from the same unified exclusion before comparing it to the estate. |
| The 2025 sunset scare | Applies an older article's warning that the exemption reverts to about $7,000,000 in 2026. | Uses the permanent $15,000,000 OBBBA figure -- that sunset was cancelled, not merely delayed. |
| Is anything I enter uploaded anywhere? | N/A | No. The calculator runs entirely in your browser; nothing is sent to a server. |
Assuming a married couple automatically gets $30,000,000 just for being married. The second $15,000,000 only applies if a surviving spouse actually elects portability of a deceased spouse's unused exclusion (DSUE) by timely filing Form 706 -- it is not automatic.
Assuming the generation-skipping transfer (GST) exemption is portable between spouses the same way the estate/gift exclusion is. It is not, and never has been -- a deceased spouse's unused GST exemption cannot be added to a survivor's own.
Forgetting that lifetime taxable gifts reduce the exclusion available at death. Estate and gift tax share one unified exclusion -- a taxable gift made years earlier uses up part of the same bucket that would otherwise shield the estate.
Relying on an older article warning that the exemption would revert to roughly $7,000,000 at the start of 2026. That sunset was real under prior law, but the One Big Beautiful Bill Act permanently cancelled it and set the 2026 exclusion at $15,000,000 instead, with no expiration date.
No. Neither this calculator nor a by-hand worksheet built from this page knows about a marital deduction, a charitable bequest, valuation discounts, or state estate tax. Both apply the same published federal exclusion, portability, and rate rules to the numbers you enter; verify against a qualified estate planning attorney or CPA before relying on either.