Free Ontario bonus tax withholding estimator using the CRA T4032 annualization method. Tax year 2026.
OntarioBonusTaxCalc.ca is a free Ontario bonus tax withholding estimator. It implements the CRA T4032-ON annualization method — the same method payroll software uses to determine how much income tax, CPP, and EI your employer withholds from a bonus payment.
The calculator is designed for Ontario employment income only. It covers tax year 2026 rates and thresholds, sourced directly from CRA T4032-ON, ESDC, and CRA CPP rate tables. All calculations run locally in your browser — no data is sent to any server.
This is not a T1 tax return calculator. It estimates employer withholding — not your actual annual tax liability. Withholding may be higher or lower than what you ultimately owe, and the difference is reconciled when you file your T1 return each spring.
This tool does not constitute tax advice. It does not model self-employment income, investment income, RRSP contributions beyond the TD1 claim, or multi-employer situations. For personal tax planning, RRSP strategy, or complex employment situations, consult a qualified CPA or tax professional.
Ontario employees receiving a bonus often do not know how much will be withheld. The CRA annualization method applies your marginal tax rate to the entire bonus in one pay period — a result that rarely matches intuition. This calculator gives Ontario employees a transparent, source-backed estimate of what to expect on their paycheque.
The calculator covers federal and Ontario income tax withholding, CPP base and additional contributions (including CPP2), EI premiums, the Ontario surtax, and the Ontario Health Premium. It accounts for year-to-date CPP and EI contribution limits so that employees nearing annual maximums see reduced deductions.
This calculator is part of the Calc-HQ.ca Ontario payroll calculator network, which includes tools for take-home pay, commission income, severance, raise, and self-employment tax estimates. See the footer for related tools.