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Your refund is the tax withheld minus the tax you owe, nothing fancier. With $75,000 of pay and $14,000 withheld in Ontario, the calculator finds $12,705 of tax owed and a refund of $1,295. Type in the boxes from your T4 to try your own year.
Where do I find each number?
Most of it’s printed on your slips. Employment income is box 14 of the T4, and income tax withheld is box 22. Paid tax instalments during the year? Add them to the withheld amount. Deductions cover things like an RRSP contribution, child care costs and union dues, and other credit amounts take claims such as a spouse amount.
| Input | Where to find it |
|---|---|
| Employment income | T4, box 14 |
| Income tax withheld | T4, box 22, plus instalments |
| Other taxable income | Interest, rent, pensions |
| Deductions | RRSP receipts, child care, union dues |
| Province | Where you lived on 31 December |
Got more than one T4? Add the box 14 amounts together and do the same with box 22. People with two jobs are the ones most likely to be surprised in spring, since each employer withholds as if theirs were the only paycheque.
What do refunds look like in Ontario?
The default is $75,000 of pay with $14,000 withheld. Taxable income is $74,273, income tax is $12,704.65 and the refund is $1,295.35.
Lower the withholding to $10,000 and the same person owes $2,704.65. Employers deduct tax by formula, so if you changed jobs or had a second income partway through the year, the formula doesn’t know about it and you can land on the wrong side.
Now go back to the default and add a $5,000 RRSP deduction. Taxable income falls to $69,273, tax drops to $11,072.15 and the refund grows to $2,927.85. That’s $1,632.50 more than before, about a third of the contribution coming straight back.
One more to try. $60,000 of pay with $8,000 withheld gives tax of $8,320.50 and a balance of $320.50. That shortfall is small, and it would flip to a refund with a modest RRSP deduction.
Is a big refund good news?
Not really, and a balance isn’t bad news either. It’s tempting to treat a refund as a prize, but it’s your own money coming back late. A big refund means more tax was held back than your year needed. A balance owing means too little was. Both just settle the gap between what you’ve paid and what the rules require. Run the tool before you file, and again after each new slip that turns up in the mail or in your online account, so April doesn’t bring a surprise you couldn’t have seen coming.
What should you do with the result?
A refund means too much tax came off your pay, so the estimate is a prompt to check your slips and file, not a bonus to plan around. A balance owing is worth knowing early, because the payment date does not move. If you are close to zero, small changes such as an RRSP receipt or a missing slip can flip the sign.
If the same gap shows up every year, the fix is usually at the source. Our page on the Alberta TD1 form shows how the withholding claim works, and the same idea applies in every province. After you file, the CRA sends a notice of assessment, and how to read it explains what each part means. The filing guide covers the steps in order.
Why might my real refund differ?
- Credits and benefits missing from the tool can raise a refund.
- Tuition, health costs and gifts to charity have no box of their own, so use the other credit amounts box or the tax deductions and credits calculator.
- A late T4 slip, a second employer or unreported interest can move the result.
- A rounding difference of a few bucks is normal. The CRA works from your slips and may reach a slightly different figure on your notice of assessment.
When is the balance due, and what if I owe?
A balance owing is due by 30 April, even if you file later. For the 2026 tax year that is Friday, April 30, 2027, and the CRA lists June 15, 2027 as the filing date for self-employed people. After the payment date the CRA charges daily compound interest on what’s still unpaid, starting the day after it was due, according to its page on line 48500, balance owing. Self-employed people get until 15 June to file, but the payment date stays 30 April. The CRA's own page on due dates still showed the 2025 year (April 30 and June 15, 2026) when we looked in November 2026, so confirm the 2027 dates there.
If you expect a big one every year, the tax instalments calculator tells you if quarterly payments are needed. Curious what your next dollar of income costs? Try the marginal tax rate calculator. For the full yearly estimate, open the income tax calculator.
Official page on this topic: Canada Revenue Agency: Tax refunds.
Where the numbers come from
Tax steps, the personal amount and the CPP and EI credits are 2026 figures from Canada.ca and each province, last checked on 29 September 2026. In November 2026 we confirmed the CRA 2026 federal and provincial brackets (Quebec excepted, and the Manitoba brackets differ between two CRA pages), plus the federal basic personal amount of $16,452 and the $181,440 threshold against the CRA's 2026 TD1 form, and the federal brackets against the CRA's 2026 rates. We aren’t connected to the CRA or any government body, and the result is an estimate, not an assessment.
About this calculator
- What it does
- Estimate your refund or balance owing from your income and the tax already withheld.
- Category
- Income Tax
- Last checked
- November 2026
- Result type
- Estimate for information only, not tax advice.
Frequently asked questions
How do I work out my refund by hand?
Add the tax withheld, from box 22 of your T4, and any instalments you paid. Then subtract your total tax for the year. A positive answer is a refund, and a negative answer is a balance to pay by April 30. The calculator does the tax step for you from your income and province.
Which slip shows the tax withheld?
Box 22 of your T4 shows income tax deducted. If you had more than one employer, add up box 22 on every T4, and do the same with box 14 for employment income. Add any tax instalments you paid during the year, since they count toward the tax you already paid.
What does an RRSP deduction do to the result?
It lowers taxable income, so the tax falls and the refund grows. On $75,000 of pay in Ontario with $14,000 withheld, a $5,000 deduction lifts the refund from $1,295 to $2,928. That is $1,632.50 more, about a third of the contribution, because the money comes off at your marginal rate.
When is a balance due?
The payment date for a balance owing is April 30, even if you file later. For the 2026 tax year that is April 30, 2027. Self-employed people get until June 15 to file, but the payment date stays April 30. After that the CRA charges daily compound interest on the unpaid amount.
Why would my actual refund be different?
Credits and benefits the tool leaves out can raise it, such as tuition, medical costs and charitable gifts. A late slip, a second employer or unreported interest can change your income. The CRA works from your slips and may land a few dollars away on your notice of assessment.
Is a big tax refund good news?
Not really. A refund is your own money coming back, and a big one means more tax was held back than your year needed. A balance owing means too little was. Both only settle the gap between what you paid and what the rules require, so run the tool before you file.
Sources and updates
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