Methodologies

These methodology pages explain how calculators across the Calc-HQ network work, including the assumptions, rates, formulas, and authoritative sources used.

• Ontario Income Tax Methodology

  Learn how Ontario income tax calculations are performed, including federal and provincial tax brackets, credits, surtaxes, CPP contributions, and the assumptions used throughout the calculation process.

• Ontario Bonus Tax Calculator Methodology

  How the Ontario Bonus Tax Calculator estimates bonus withholding using the CRA T4032 annualization method, including CPP/EI thresholds, Ontario surtax, and Ontario Health Premium for 2026.

• Ontario Take-Home Pay Calculator Methodology

  How the Ontario Take-Home Pay Calculator estimates net take-home pay for Ontario employees, including federal and Ontario tax brackets, CPP contributions, EI premiums, Ontario surtax, Ontario Health Premium, and pay frequency conversion for 2026.