Quick answer
A pro-rated salary is the full-time salary multiplied by the share of a normal year you work: weekly hours divided by full-time hours for part-time work, or months worked divided by 12 for a part-year job. For a $70,000 full-time salary in 2026, working 24 hours of a 37.5-hour week pays $44,800.00 a year, and working 6 of 12 months pays $35,000.00.
How pro-rating works
Pro-rating just means scaling a full-time salary down by the share of a normal year you actually work. That share — the ratio — comes from one of two comparisons: how many hours you work each week against a full-time week (part-time work), or how many months or weeks you're actually on the payroll against a full year (part-year work). Multiply the full-time annual salary by that ratio and you have the gross pay you'll genuinely earn. Everything else on this page — the tax, the CPP, the EI, the payroll tax in the Northwest Territories and Nunavut, and the refund estimate — is computed on that pro-rated figure, using the same federal and provincial payroll-tax engine as our Take-Home Pay Calculator, because tax is owed on what you actually earn in the year, not on the full-time salary printed in your contract.
Part-year: pro-rated gross = full-time salary × (months or weeks worked ÷ 12 or 52)
Part-time hours: 37.5 vs 40
The ratio for part-time work depends entirely on what your employer counts as a full-time week, and Canada has no single legislated answer to that. This calculator lets you pick either one as the full-time reference. The Canada Labour Code caps standard hours of work at eight hours a day and forty hours a week (s. 169(1)). A 37.5-hour week, a 7.5-hour day, is the figure in the Treasury Board's Directive on Terms and Conditions of Employment for Certain Excluded and Unrepresented Groups and Levels, which sets normal hours of work at 7.5 a day and 37.5 a week for its Groups I to IV. A full-time week and an overtime threshold are different things: 40 hours a week is the overtime threshold under the Canada Labour Code and in most jurisdictions, but not everywhere — Ontario's Employment Standards Act pays overtime only after 44 hours in a week. Check your offer letter or contract for the number your own employer actually uses before you rely on this calculator's ratio.
Part-year work and the tax-time refund
Part-year work creates a genuine mismatch that steady part-time work usually doesn't. A part-time paycheque already reflects the reduced hours every period, so payroll's own math — this period's pay times the number of pay periods in a year — lands on the correct annual figure throughout. A part-year employee, by contrast, is usually paid at the full rate while working; payroll can't know the job will end in June, so it withholds tax on every cheque as if that rate will continue all 12 months. Someone paid biweekly at a $70,000 rate has tax withheld as though they'll earn $70,000 for the year, even working only six months for $35,000. Because Canada's brackets and credits are sized for a full year, tax withheld against the $70,000 assumption runs higher than what $35,000 of real income actually owes — and that gap comes back as a refund once you file, reporting the true, lower figure. This calculator estimates it directly: full-year tax at your withholding rate, times the share of the year you worked, minus what's actually owed on your pro-rated income.
CPP and EI don't have the same gap
Income tax is withheld on an annualized assumption, but CPP isn't: its $3,500 basic exemption is divided across the pay periods in a year before any deduction is calculated — $3,500 ÷ 26 for biweekly pay, per CRA's T4127 payroll formulas — and one share is applied to each cheque. There is no full-year assumption to unwind, but there is a smaller gap running the other way: a part-year employee only ever receives part of the exemption through payroll, while the tax return allows the full $3,500 for the year, so the CPP taken on the unused portion comes back as a CPP overpayment on Schedule 8 — 5.95% of $1,750, about $104, for six months of biweekly pay below the CPP ceiling. That is small enough that this calculator leaves it out of its refund estimate, which covers income tax only. (Switching employers mid-year is a separate case: each employer runs its own exemption and cap independently, which is how contributions across two employers can add up to more than the annual maximum and get refunded — not modelled here.) EI has no exemption to prorate at all — a flat percentage from the first dollar to the annual maximum — so it creates no gap of the CPP kind, with one exception described at the end of this section. The payroll tax of the Northwest Territories and Nunavut works the same way: it is a flat 2% of the pay actually paid, withheld from each cheque, so it leaves no gap to refund and is not part of the refund estimate. The exception is a very small year of insurable earnings: section 96(4) of the Employment Insurance Act refunds all the EI premiums deducted when a person's insurable earnings for the year are $2,000 or less, and section 96(5) refunds part of them when earnings are a little over $2,000 (the Act has a separate rule for self-employed people to whom its Part VII.1 applies). A $20,000 salary for one month is $1,666.67, which is within the first rule. This calculator's refund estimate covers income tax only, so it does not show that EI refund.
Worked example — a $70,000 salary in Ontario, two ways
Part-time: $70,000 full-time, working 24 of a 37.5-hour week, Ontario.
- Ratio: 24 ÷ 37.5 = 0.64. Pro-rated gross: $70,000 × 0.64 = $44,800.00.
- Federal tax $3,312.32, Ontario tax $1,895.48, CPP $2,457.35, EI $730.24.
- Net pay: $36,404.61 for the year — an 11.6% average tax rate.
- Because every paycheque already reflects the reduced hours, payroll's own annualizing lands on this same $44,800.00 all year — no meaningful refund from the part-time hours alone.
Part-year: the same $70,000 full-time rate, working 6 of 12 months, Ontario.
- Ratio: 6 ÷ 12 = 0.5. Pro-rated gross: $70,000 × 0.5 = $35,000.00.
- Federal tax $2,044.32, Ontario tax $1,288.10, CPP $1,874.25, EI $570.50.
- Net pay: $29,222.84 — a 9.5% average tax rate, lower than the part-time case because the pro-rated income itself is lower and Canada's brackets are progressive.
- Full-year tax on $70,000 would be $11,133.91 (fed + Ontario); withheld across six months of paycheques at that rate, that's roughly $5,566.96 — against $3,332.41 actually owed on $35,000. The difference, about $2,234.55, is the estimated refund.
Figures above are rounded to the cent for readability; the calculator itself carries full precision. That is why the $3,332.41 of tax on $35,000 is one cent less than its rounded federal and Ontario parts added together: the two are added first and rounded once. Both examples use the same shared tax engine as the Take-Home Pay Calculator — see that page for the full federal and provincial derivation.
FAQ
How do I calculate pro-rated pay?
Multiply the full-time annual salary by a ratio. For part-time work, the ratio is the hours you actually work each week divided by your employer's full-time reference (this calculator offers 37.5 or 40 hours) — a $70,000 job at 24 of 37.5 hours a week pays $70,000 × (24 ÷ 37.5) = $44,800 a year. For part-year work, the ratio is the months or weeks you'll actually work divided by 12 or 52 — six months of a $70,000 job pays $70,000 × (6 ÷ 12) = $35,000 for the year. This calculator taxes whichever pro-rated figure you actually earn, not the full-time salary.
Why is my paycheque taxed as if I earn my full salary, even though I'm only working part of the year?
Payroll doesn't know in advance that you'll stop working partway through the year — it withholds tax on every paycheque as though that pay rate will continue for the full 12 months, because that's genuinely your rate of pay while you're on the job. Someone paid $2,692 biweekly has tax withheld as if they'll earn $70,000 for the year, even if they only work six months and actually earn $35,000. Since Canada's tax brackets and credits are set for a full year of income, the tax withheld against a $70,000 assumption is higher than what $35,000 of real income actually owes — the gap is refunded when you file your return.
Should I use 37.5 or 40 as my full-time hours?
There's no single national answer — use whatever your employer defines as a full-time week, which may be stated in your offer letter or contract. The Canada Labour Code caps standard hours of work at 40 a week, and the Treasury Board's Directive on Terms and Conditions of Employment for Certain Excluded and Unrepresented Groups and Levels sets normal hours at 7.5 a day, 37.5 a week, for its Groups I to IV; this calculator lets you pick either as the full-time reference. A full-time week is not the same thing as an overtime threshold: 40 hours is the weekly overtime threshold federally and in most jurisdictions, but not everywhere — Ontario's Employment Standards Act, for example, sets overtime after 44 hours, not 40.
Does CPP get pro-rated the same way, and will I get a refund on it too?
Not the same way, and only a little. Payroll divides CPP's $3,500 annual exemption across the pay periods in a year — $3,500 ÷ 26 for biweekly pay, for instance — and applies one share to each cheque you actually receive, so six months of work uses only half the exemption. Your tax return then allows the full $3,500 for the year (Schedule 8 prorates it only in special cases, such as the year you turn 18 or 70), and the CPP taken on the unused half comes back as a CPP overpayment: 5.95% of $1,750, about $104, for six months of biweekly pay below the CPP ceiling — small enough that this calculator's refund estimate, which covers income tax only, leaves it out. EI has no exemption to prorate at all — it's a flat rate from the first dollar up to the annual maximum — so a part-year job does not create a gap like CPP's, with two exceptions this calculator does not estimate. One is hitting the annual cap twice by working for two employers in the same year. The other is a very small year of insurable earnings: under section 96(4) of the Employment Insurance Act, a person whose insurable earnings for the year are $2,000 or less is refunded all the EI premiums deducted, and section 96(5) refunds part of them when earnings are a little over $2,000 (the Act has a separate rule for self-employed people to whom its Part VII.1 applies). A $20,000 salary for one month is $1,666.67, which is within the first rule. The refund estimate on this page covers income tax only, so it does not show that EI refund.
Could I end up owing money instead of getting a refund?
For a straightforward part-year employee with a single job and no other income, no — Canada's progressive tax brackets and fixed credits mean tax on a smaller income is always proportionally lower, so the withholding-vs-actual gap this calculator estimates is a refund, not a bill. Owing money at tax time usually comes from something this calculator doesn't model: a second job, self-employment income, EI benefits between jobs, or claiming credits and deductions that reduce what should have been withheld.
Does this work for part-time hours that change from week to week?
Enter your average or typical hours — the calculator applies one steady ratio for the whole year. If your hours genuinely vary week to week, payroll re-annualizes each individual paycheque rather than your average, so your real pay and tax will bounce around period to period in a way a single annual estimate can't capture; the tax owed at year-end still depends on your true total earnings for the year, which this calculator can approximate if you enter your expected total hours.
This page is general information based on published 2026 federal and provincial payroll rules, not tax or financial advice. Your own return may differ — talk to a licensed accountant about your specific situation.