Capital gains check

Will you owe capital gains tax if you sell your home?

Enter what you paid, when, your ZIP, and what selling would cost. You get the gain on today’s estimated value, how much of it the $250,000 or $500,000 exclusion covers, and what is left to tax, from the federal FHFA index and the IRS rules with the math shown.

Your gain and the exclusion

Fill in the fields and press the button. The example below is a real result.

Informational only, not tax advice, not professional advice and not an appraisal. The sale price is an area average; the tax rules have exceptions this tool does not model.

Methodology

The gain. Gain = selling price − selling expenses − adjusted basis, as IRS Publication 523 lays it out. The selling price is the estimate from the FHFA House Price Index: what you paid × (index now ÷ index at purchase) for the smallest of your ZIP, county, metro or state with data (annual county and ZIP files dated March 31, 2026; quarterly master file through 2026 Q2). Selling expenses are the percentage you enter, applied to that price. Adjusted basis is what you paid plus the improvements you enter.

The exclusion. IRS Topic 701 allows up to $250,000 of gain to be excluded from income, or $500,000 on a joint return, when you owned the home and used it as your residence for at least 24 months of the five years before the sale and did not exclude gain on another home in the prior two years. The tool subtracts the smaller of the gain and the allowed amount; what remains is the taxable gain. If you answer no to the two-year question it excludes nothing and names the partial exclusion Publication 523 provides for work, health and unforeseeable-event moves, which it does not compute.

What it stops short of. No tax rate. The taxable part is a long-term capital gain whose federal rate depends on your taxable income, and some states tax it as well. Basis here omits purchase closing costs that also add to it and any depreciation that reduces it. A loss on a main home is not deductible.

What this estimate cannot know

Your house. The sale price tracks the area’s average. Renovations, condition and lot are not in it, and a real offer can sit far from it.
Sales the index never sees. Per FHFA’s own description, the index is built from repeat sales and appraisals on conforming mortgages. Cash, jumbo, FHA and VA purchases are not in it.
Your full tax picture. Prior exclusions, rental or home-office use, a divorce or a death, an inherited or gifted home, and a like-kind exchange all change the answer under rules this tool does not model.
The future. The index is history and the tax rules are as of the review date. It is not an appraisal and not a forecast.

Last reviewed: September 2026. Data vintage: FHFA master file 2026 Q2; annual county and ZIP files dated March 31, 2026; IRS Topic 701 and Publication 523 (2025).

Frequently asked questions

How much gain can I exclude when I sell my home?

Up to $250,000, or $500,000 on a joint return, if you owned the home and lived in it as your main home for at least 24 months of the five years before the sale and did not exclude gain on another home in the two years before (IRS Topic 701). The amounts are set in the tax code and are not indexed to inflation.

What counts as the gain?

Selling price minus selling expenses minus adjusted basis (Publication 523). Basis is what you paid plus improvements that add value or prolong the home's life, such as a roof, an addition or central air, plus certain purchase closing costs. Repairs and painting do not count, and depreciation taken for a home office or rental use lowers it.

Where does the sale price come from?

From the FHFA House Price Index: your purchase price scaled by the change in the smallest area with data since you bought, the same estimate as the home value since purchase calculator. It is an area average, not an offer. If you have a real contract price, use it in place of the estimate and the rest of the math is unchanged.

What tax rate applies to the taxable part?

A home held more than a year is a long-term capital gain, taxed at 0, 15 or 20 percent federally depending on your taxable income, possibly plus the 3.8 percent net investment income tax, and some states tax it too. This tool stops at the taxable amount because the rate depends on your whole return, which it cannot see.

Guides

Will I Owe Capital Gains Tax When I Sell My House? The Exclusion, Worked ThroughSale price minus selling costs minus what you have in the home is the gain. How the $250,000 and $500,000 exclusion applies, worked through on a real purchase.

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