Capital Gains Tax Estimator
Free capital gains tax estimator. Calculate short-term and long-term capital gains tax from cost basis, sale proceeds, holding period, and income brackets, all in your browser.
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What is Capital Gains Tax Estimator?
The Capital Gains Tax Estimator approximates the tax owed when you sell an investment for a profit. It classifies the gain from your holding period and applies US federal brackets with income stacking or a custom flat rate, all offline in your browser.
Key Benefits
- Instant short-term vs long-term classification from holding days.
- Marginal-bracket math that stacks your gain on real income.
- Custom flat-rate mode for any country or quick scenarios.
- Clear breakdown: gain, rate applied, tax, and net proceeds.
- No signup, no upload, no data collection.
Common Use Cases
- •Comparing the tax impact of selling now versus after one year.
- •Planning the sale of stocks, ETFs, or crypto holdings.
- •Estimating tax before listing an investment property.
- •Teaching how marginal brackets and stacking work.
How to Use the Capital Gains Tax Estimator
- Pick a mode: Keep the US federal brackets mode for US-style estimates, or switch to a custom flat rate.
- Enter your numbers: Fill in cost basis, sale proceeds, and (in brackets mode) your annual ordinary income.
- Set the holding period: Enter the days you held the asset - over 365 days is long-term.
- Read the estimate: Review the gain, gain type, rate applied, estimated tax, and net proceeds after tax.
Key Features
- Classifies gains as short-term or long-term from holding days.
- US federal brackets (single filer) with marginal income stacking.
- Long-term tiers of 0%, 15%, and 20% on the gain portion.
- Custom flat-rate mode for other countries and what-ifs.
- Handles losses gracefully with zero tax and a clear label.
- Runs entirely in your browser - no upload, no account.