TaxMath

About TaxMath

TaxMath is a free, browser-based tax estimation and comparison tool that helps individuals compare tax outcomes across US states and Canadian provinces — all in one view.

What TaxMath Does

TaxMath calculates and compares estimated taxes for any combination of US states or Canadian provinces. It covers:

  • Federal and state/provincial income taxes using current marginal-bracket tables for tax years 2022 through 2026.
  • Long-term and short-term capital gains taxes at federal and state levels.
  • Corporate tax rates (simplified C-Corp flat rate) for federal and state/provincial levels.
  • Standard deduction modeling (single filer) where available.
  • Canadian dividend tax credits for eligible and non-eligible dividends.
  • Scenario saving and reloading so you can compare results across different income levels and years.

How to Use TaxMath

  1. Choose United States or Canada on the calculator tab.
  2. Select the tax year you want to model.
  3. Enter your income figures: regular income, capital gains, and (for the US) corporate income.
  4. Select the states or provinces you want to compare — the results table updates instantly.
  5. Optionally toggle standard deduction (US) or view dividend credit breakdowns (Canada).
  6. Save your scenario for later using the Scenario Manager at the bottom of the calculator.

Important Limitations

TaxMath is for estimation and comparison only. It is not a tax preparation tool and should never be used as a substitute for professional tax advice. Specific limitations include:

  • Single-filer brackets only — no married filing jointly, head of household, etc.
  • No modeling of credits, surtaxes, AMT, NIIT, or phase-outs.
  • No local (city/county) tax modeling.
  • Long-term capital gains only — short-term gains should be entered as regular income.
  • Canadian 2026 capital-gains inclusion uses a simplified single factor; actual law may require tiered treatment.

Tax Data Sources

Rate tables are sourced from official IRS publications, CRA publications, and state/ provincial tax authority websites. You can browse the underlying data on our Tax Tables page, which includes links to primary sources and verification dates for each jurisdiction. If you spot an error, please contact us.

Frequently Asked Questions

What is TaxMath?

TaxMath is a free, browser-based tax calculator that lets you compare income taxes across all 50 US states and Canadian provinces. All computation happens locally in your browser — no sign-up or server-side processing needed.

Is TaxMath free to use?

Yes. TaxMath is completely free with no account required.

Does TaxMath store my financial data?

No. All figures you enter are processed in your browser. Saved scenarios use your browser's local storage and are never sent to any server.

How accurate is TaxMath?

TaxMath provides directional estimates. It models marginal brackets and standard deductions accurately, but it does not account for credits, surtaxes, AMT, or other complexities. Always verify with official sources or a tax professional before making financial decisions.

Contact

Suggestions, corrections, and feedback: [email protected]