USA & Canada · per-state / per-province · 2025 tax year
Same numbers, programmatically. This page runs entirely in the browser; the same engine is also available as a JSON API and MCP server (see llms.txt). The 2025 brackets for every US state and Canadian province plus the calculation are a standalone, dependency-free script for Node or a browser: https://www.a3sec.net/tools/engines/tax-engine.js. Example: curl -sO https://www.a3sec.net/tools/engines/tax-engine.js && node -e "const T=require('./tax-engine.js');console.log(JSON.stringify(T.summarize(T.computeTax({country:'US',region:'CA',filing:'single',salary:95000})),null,1))"
Prefill by URL: tax.html?country=CA®ion=ON&salary=120000&agent=1. Parameters: country (US|CA), region (two-letter state or province code), filing (single|joint, US only), salary, capgains, dividends, capType (long|short, US only), divType (eligible|noneligible; for the US eligible = qualified, noneligible = ordinary), lang (en|uk), theme (dark|light); agent=1 opens this panel. Results appear below as JSON (element id resultsJson).
Model (2025 tax year). US: standard deduction $15,750 single / $31,500 joint; ordinary brackets; long-term gains and qualified dividends stacked on top at 0 / 15 / 20%; 3.8% NIIT above $200k / $250k MAGI; FICA 6.2% up to $176,100 plus Medicare 1.45% (+0.9% above $200k / $250k); state tax from the bundled tables (none, flat or brackets; Washington capital-gains tax). Canada: CPP 4.95% + 1% enhanced (deductible) + CPP2 4%, EI 1.64% (Quebec: QPP, reduced EI, QPIP), 50% capital-gains inclusion, dividend gross-up with federal and provincial credits, federal and provincial brackets with basic personal amounts (grinds applied), 16.5% Quebec abatement. Ontario surtax (20% above $5,710 basic tax plus 36% above $7,307) and health premium ($0–$900) are included; surtax precedes the dividend credit. Colorado and Idaho use the federal standard deduction; Georgia uses $12,000 single / $24,000 joint. Idaho also applies its $4,811 / $9,622 zero-rate band. Other states’ deductions and other credits, surtaxes, local taxes and phase-outs remain simplified. Money is in the local currency (USD / CAD).
No code execution? The same calculation is available as a JSON API (https://www.a3sec.net/api) and as MCP tools at https://www.a3sec.net/api/mcp. All three calculators are described in https://www.a3sec.net/llms.txt. Estimates only — not tax advice.
Current results (JSON, updated on every change):
{}