QSBS tax calculator

Estimate the federal tax on a sale of qualified small business stock under the rules before and after July 4, 2025.

Calculator

Set when you got the stock, how long you held it, what you paid, and what you sell it for.

When you got the stock

Years held before the sale3

What you paid for the stock

Your basis. For founders, often a few thousand dollars.

What you sell it for

Conditions that the calculator cannot test

The company is a US C corporation

Not an LLC, not an S corporation.

You got the stock directly from the company

Shares bought from a different holder do not qualify.

At least 80% of the assets are in a qualified active business

Not health, law, consulting, finance, hotels, and other excluded fields.

Gross assets stayed at $75M or less before and just after the issue

Cash plus the tax basis of other assets, not the valuation.

Federal tax on this sale

At 3 years, 50% of the eligible gain is excluded. The eligible gain stops at $15M, the greater of $15M or 10 × your $3K basis.

The $7.5M of eligible gain that is not excluded pays 31.8%. The $25M more than the limit pays 23.8%. You pay $8.33M, not $9.52M.