Capital Gains Tax Calculator

How to use this calculator

Enter sale proceeds, cost basis, estimated tax rate, and selling fees. The calculator estimates net gain and rough tax owed.

When this calculator is useful

• Planning before selling investments
• Understanding cost basis impact
• Comparing before-tax and after-tax returns

Important limitations

This is not tax advice. Holding period, income level, state taxes, wash sales, depreciation, NIIT, and other rules may apply.

For best results, run at least three cases: a conservative case, a middle case, and a stretch case. If a small change in inputs creates a big change in the answer, that is a sign the decision may be sensitive to rates, fees, timing, or market performance.