Capital Gains Tax Estimator
Free capital gains tax estimator.
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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.
Frequently Asked Questions
What is the difference between short-term and long-term gains?
Assets held 365 days or less produce short-term gains taxed as ordinary income. Holding longer than a year qualifies for long-term tiers, which are usually lower.
How are the long-term rates applied?
The estimator stacks your gain on top of your ordinary income and taxes only the gain slice: 0% up to 47,025 USD, 15% up to 518,900 USD, and 20% above (single-filer thresholds).
Does this tool give exact tax figures?
No - it is a simplified estimator that ignores deductions, state taxes, and special rules. Use it for planning, and consult a tax professional for filing.
What happens if I sell at a loss?
The tool shows the loss amount and sets the estimated tax to zero. Real-world losses can offset other gains, which this simplified view does not model.