How to calculate capital gains tax
Tax = (Sale price − Purchase price) × applicable rate
Worked example. Estimated capital gains tax: $750.
Example inputs — Purchase price: $10,000; Sale price: $15,000; Held longer than 1 year?: Yes — long-term; Taxable income (single filer): $80,000. Starting values are illustrative.
From George Guju, founder of Calculyn · Educational calculator guidance, not professional advice.
How it works
Short-term gains (held under a year) are taxed as ordinary income; long-term gains get lower 0%, 15%, or 20% rates based on your taxable income.
Assumptions & limitations
- Single filer, 2026 federal brackets
- Short-term gains approximated at a 24% ordinary rate
- State taxes and the 3.8% net investment income tax not included
Formula and assumptions reviewed October 2026 by the Calculyn team. How we build our calculators
Frequently asked questions
What if I sold at a loss?
Capital losses offset capital gains, and up to $3,000 of net loss can offset ordinary income per year.
Does this include state tax?
No — many states also tax capital gains. This estimates federal tax only.