Updated Checked by the Tax-Services.ca editorial team How we check
A tax return estimator gives you a refund or a balance owing before you file, and it’s only as good as the three numbers you type in: your income, the tax already taken off it and your deductions. Put in $75,000 of Ontario pay with $14,000 withheld and our estimate is a $1,295.35 refund.
What do you need before you use a tax return estimator?
Start with your T4. Box 14 is your employment income and box 22 is the income tax your employer already sent to the CRA. Those two figures do most of the work.
Then add anything the T4 doesn’t show. That means interest, rent after costs, pension income and side earnings. Then list deductions such as RRSP contributions, child care and union dues, and any extra credit amounts you can back up with paper.
The CRA’s own rule for the answer is short. Your refund is your credits minus your total payable, and if the sum goes the other way you owe. Total payable is line 43500 on the return, and the notice of assessment shows both figures after you file.
How much does each input change the estimate?
Start with an $85,000 salary in Ontario, where the tax comes to $15,551.05. Then change one thing at a time in the tax refund calculator.
| Change to the $85,000 case | Income tax | Difference |
|---|---|---|
| Nothing (baseline) | $15,551.05 | none |
| $6,000 deduction, such as an RRSP | $13,772.05 | saves $1,779.00 |
| $2,000 of other taxable income | $16,144.05 | costs $593.00 |
| $5,000 of extra credit amounts | $14,598.55 | saves $952.50 |
A deduction beats a credit of the same size.
It comes off your income at your top rate, which for this salary is well above the credit rate, and that’s why a $6,000 deduction saves $1,779.00 while $5,000 of credit amounts saves $952.50. Per dollar, the credit returns roughly a fifth of the amount at these levels.
Does the province change the answer?
A lot. The federal tax on $85,000 of employment income is $10,226.60 everywhere except Quebec, so the gap comes from the province. Here are total income tax figures from the income tax calculator.
| Province | Total income tax on $85,000 | Average rate |
|---|---|---|
| Alberta | $15,196.98 | 17.9% |
| Ontario | $15,551.05 | 18.3% |
| Saskatchewan | $16,992.61 | 20.0% |
| Manitoba | $17,798.27 | 20.9% |
| Quebec | $18,079.68 | 21.3% |
| Nova Scotia | $19,775.79 | 23.3% |
We left out British Columbia on purpose. Its lowest 2026 rate is reported differently by different official sources, and we won’t guess. Quebec’s return is separate from the federal one, so treat that row as a rough guide.
The spread is big. Nova Scotia’s total is $4,578.81 higher than Alberta’s on the same pay, which is about $380 a month.
Why is your real refund different?
Because an estimator only sees what you tell it, and it can’t guess at the rest of your life. Ours counts the basic personal amount, the Canada employment amount and the CPP or QPP and EI credits. It skips benefits, refundable credits and most other claims, so a family with child care costs can land far from the printed figure.
Withholding is the other trap. Take a $52,000 Ontario salary, where the estimate says $6,625.43 of tax. If your employer withheld $6,300 you’d owe $325.43. If it withheld $7,200 you’d get $574.57 back. Same tax, different cheque.
A refund isn’t a bonus. It’s your own money coming back, so a big one usually means the government held your cash all year for nothing. If you’re self-employed, use the self-employed tax calculator, since nobody withholds anything for you.
What should you do with the result?
If the estimate says refund, don’t spend it yet. It’s a ballpark until the CRA assesses your return, and one missed slip can move it by hundreds. If it says you owe, set the cash aside now so April doesn’t hurt.
Owing two years running is a hint that something is off. A second job, a side gig or investment income with no tax taken off are the usual reasons. Tax instalments are one way to even it out, and the tax instalments calculator shows what the quarterly payments would be.
And a quick sanity check never hurts. On $85,000 in Ontario the average rate is 18.3%, so if your estimate lands near 5% or 40% of pay, something went in the wrong box.
When do you have to file and pay?
For the 2025 return, the CRA set 30 April 2026 for both filing and payment. If you or your spouse ran a business, the filing date moved to 15 June 2026, but any balance was still due on 30 April. We didn’t find the 2026 return dates published yet, so check the CRA’s dates page in the new year.
Sources, and how we checked them
Tax rates and brackets are the 2026 figures on the Canada Revenue Agency site. The refund rule and the dates come from its pages on line 48400 and on filing due dates. We ran every example through our own engine on 30 September 2026. This is an independent guide, separate from any government body.
Frequently asked questions
What do I need for a tax return estimate?
Your T4 income (box 14), the tax withheld (box 22), and any deductions or credit amounts you can prove.
How is a refund worked out?
It's your total credits minus your total payable. If the result runs the other way, you owe the difference.
Why does my refund differ from the estimate?
The estimate leaves out benefits, refundable credits and most other claims, and your withholding may differ from what the tax works out to.
Does a bigger deduction help more than a credit?
At the same dollar amount, yes, because a deduction comes off income at your top rate.
When was the 2025 return due?
30 April 2026 for most people, and 15 June 2026 for the self-employed, who still had to pay by 30 April.
- How to file your tax return in Canada: steps and dates
What to gather, when your return is due and how to file in Canada, from the first slip to the notice of assessment that closes the year