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x402toll Capital Gains Tax Calculator
x402
x402toll Capital Gains Tax Calculator is a paid API for AI agents from x402toll.com, paid per call via x402, $0.1/call, status unknown (last checked 2026-09-13).
Calculates US federal capital gains tax using 2026 long-term bracket stacking (0%/15%/20%), short-term ordinary rates, and the 3.8% Net Investment Income Tax
Price / call$0.1
Success—
StatusUnknown
How this service works
Federal capital-gains tax: long-term stacked across the 2026 0%/15%/20% breakpoints, short-term at ordinary marginal rates, plus the 3.8% Net Investment Income Tax.
Output
A breakdown of federal capital gains tax liability: long-term tax computed by stacking gains atop ordinary income across the 2026 0%/15%/20% bracket thresholds, short-term tax at applicable ordinary marginal rates, the 3.8% NIIT if MAGI exceeds applicable threshold, and a combined total federal capital gains tax owed.
Example use cases
Example prompt
“I sold some stock this year — I have $80,000 in long-term capital gains and $15,000 in short-term gains. My MAGI is $220,000 and my ordinary taxable income is $175,000 and I file as single. What's my total federal capital gains tax including NIIT for 2026?”
Technical details
Endpoint
POSThttps://x402toll.com/v1/tax/capital-gainsWhen to prefer
Use this endpoint when you need a precise, 2026-current federal capital gains tax estimate that correctly stacks long-term gains atop ordinary income across bracket breakpoints and applies NIIT — ideal when both long-term and short-term gains are present, or when MAGI may push income over the NIIT threshold. Prefer this over a generic tax calculator when you specifically need capital gains breakdown rather than a full income tax estimate.
Side effects
- Missing required 'magi' field returns validation error
- Invalid filing status enum value returns 400 bad request
- Negative gain values may produce unexpected results if not handled
- Payment failure or insufficient USDC balance returns 402 Payment Required
- Extremely large gain values may hit numerical precision limits
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| magi | number | |
| filingStatus | string | |
| longTermGain | number | |
| shortTermGain | number | |
| ordinaryTaxableIncome | number |
Tags
x402
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