Free Calculator

You've Been Tracking the Improvements. Now See What They're Actually Worth at Closing.

A tracker tells you what you spent. This calculator turns that record into a real number: your adjusted basis, your estimated gain, and roughly what you would owe in federal and California tax at your sale price. Two tabs, built around the two situations we hear about most.

This is the third piece in our tax-basis series. If you have not seen the first two yet, they are worth five minutes: the home improvements and tax basis guide, and the California surviving spouse step-up guide.

What's in it

• Tab 1: Basis and Gain EstimatorEnter your purchase price, sale price, selling costs, and a log of your capital improvements. The sheet calculates your adjusted basis, applies the federal Section 121 exclusion (250,000 dollars single, 500,000 married filing jointly, subject to the two-of-five-year ownership and use test), and estimates federal and California tax on what is left.
• Tab 2: California Community Property Step-UpFor a surviving spouse. California is a community property state, which means both halves of the home's value, not just the half your spouse owned, can step up to fair market value on the date of death. This tab compares your tax with the step-up against what it would be without it, side by side.

Every formula cell is locked so the math cannot be accidentally overwritten. Only the fields you are meant to fill in, your numbers, dates, and project log, are open for editing.

This calculator is provided for general education and planning, not tax or legal advice. It uses simplified example tax rates and does not account for depreciation recapture, alternative minimum tax, net investment income tax, or every exception in the code. Talk to your CPA before relying on it for a return or a closing decision.