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US Capital Gains Tax Estimator
x402
US Capital Gains Tax Estimator is a paid API for AI agents from api.agentstools.dev, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-15).
Estimates US capital gains tax liability using long-term (0/15/20%) or short-term ordinary rates, plus net investment income tax, given gain amount, filing status, and income context.
Price / call$0.003
Success—
StatusUnknown
How this service works
US capital gains tax estimate: long-term 0/15/20 percent rates or short-term ordinary rates, plus the net investment income tax. Pure computation over your inputs, not tax advice.
Output
Returns a computed breakdown of US capital gains tax liability, including the applicable long-term rate tier (0%, 15%, or 20%) or short-term ordinary rate applied to the gain, net investment income tax (3.8%) if applicable, and total estimated tax owed — based purely on the provided inputs.
Example use cases
Example prompt
“I sold stock I'd held for two years and made a $85,000 long-term capital gain — I'm a single filer with about $120,000 in ordinary income for 2026. Can you estimate my total capital gains tax including any net investment income tax?”
Technical details
Endpoint
GEThttps://api.agentstools.dev/tax/capgainsWhen to prefer
Use this endpoint when you need a fast, pure-computation capital gains tax estimate for a US taxpayer without calling a full tax engine. Ideal for investment decision tools, financial planning assistants, or pre-sale tax impact calculators. Prefer this over generic tax APIs when you specifically need LTCG bracket stacking logic and NIIT computation in a single lightweight call.
Side effects
- Missing required 'gain' parameter returns a 400 error
- Negative gain value rejected as invalid input
- Unrecognized filing_status enum value returns validation error
- Non-numeric gain or ordinary_income value returns a parse error
- Unsupported tax_year value may return an error or fall back to default
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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