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Step-Up in Basis Calculator

What is the new basis after a spouse dies, and how much gain disappears? Every piece below can be linked to, so it opens in a window on your reader's screen, current as of the record. No form to fill in.

2026 law · Reviewed September 6, 2026 · The full page, with methodology and sources · the terms · All tools

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The cost, the value at death, and how the asset was titled in; the new basis, the gain erased, and the tax a later sale saves out. In a frame it carries no cookies, no tracking, and a visible link back to the methodology. Your site has to allow frames; most do. The link that opens it in a small window is on the professionals page.

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In plain words.
When someone dies, the things they owned get a fresh tax cost equal to their value that day, so the profit that built up during their life is never taxed. How much of a jointly owned asset gets this fresh cost depends on how it was titled: all of it for something they owned alone, half for something owned jointly with a spouse in Illinois. This tool takes the original cost, the value at death, and the title, and shows the new cost and the profit that disappears.
Why it matters.
It changes what a survivor should sell first and what to hold. Selling the house or the stock with the new cost may owe nothing; selling something the survivor owned alone may owe a lot.
An example.
A home bought for $200,000, worth $800,000 when the first spouse dies, owned jointly: the new cost is $500,000. Half of the $600,000 profit is gone for tax purposes; the survivor's half keeps its old cost.
Where it stops.
It does not cover property owned jointly with someone other than a spouse, which follows who paid for it, or retirement accounts and annuities, which never get the fresh cost. A rental property has its own adjustment for depreciation.

Everything here reads from one reviewed record, so a copied piece carries its year and its review date. When the law moves, the embed updates by itself; a copied table or chart keeps the year in its caption. Corrections are welcome through the contact page.