How this calculator works
An RRSP contribution is deducted from your taxable income before tax is calculated, so the value of the deduction is whatever tax you would otherwise have paid on that slice of income. This calculator computes your federal and provincial tax twice on the income you enter — once with no RRSP deduction, once with your contribution (or the deductible portion of it, if you're over your limit) subtracted — using the identical CRA T4127 annual-method tax engine as our Take-Home Pay Calculator: the same 2026 brackets, basic personal amounts, CPP/CPP2 (or QPP/QPP2 in Quebec), EI (or the reduced Quebec rate plus QPIP), Ontario's surtax and Health Premium, the BC and Ontario low-income reductions, and Quebec's own TP-1015.F-V formula. The difference between the two tax bills, federal plus provincial, is your estimated refund.
Deductible contribution = the lesser of what you enter and your estimated 2026 RRSP room
2026 RRSP room = the lesser of 18% × prior-year earned income and $33,810
Your 2026 RRSP deduction limit
CRA's own rule is that your RRSP deduction limit for a year is generally the lesser of 18% of your earned income from the previous year and that year's dollar limit — $33,810 for 2026 — plus any unused room carried forward from earlier years, minus any pension adjustment from an employer pension plan. This calculator only models the first part: 18% of the prior-year income you enter (or your current income, if you leave that field blank), capped at $33,810. Someone would need $187,833.33 of prior-year earned income to generate the full $33,810 of new room on their own, before any carryforward. If you haven't used all your room in past years, your real limit is almost certainly higher than what this page estimates — your Notice of Assessment or CRA My Account shows the actual figure.
What happens if you go over your limit
Contributing more than your deduction limit doesn't make the excess deductible — CRA still only lets you deduct up to your limit this year, and the extra carries forward as room for a future year. Where it gets costly is if that excess sits in the account: CRA allows up to $2,000 of over-contribution without any penalty (a buffer meant mainly to cover small timing errors), but for every dollar over your limit beyond that $2,000, and for every month it remains un-withdrawn and un-absorbed by new room, CRA charges a tax of 1% per month. This calculator flags both cases separately — over your limit but within the $2,000 buffer, and over the buffer itself.
Worked example — $80,000 income, $10,000 contribution, Ontario
Employment income $80,000, prior-year income also $80,000 (left as the default), RRSP contribution $10,000, Ontario.
- Room check: 18% × $80,000 = $14,400, well under the $33,810 dollar limit — so the full $10,000 contribution is deductible.
- Federal tax: $9,242.60 before the deduction, $7,192.60 after — a federal refund of $2,050.00.
- Ontario tax: $4,885.26 before, $3,820.26 after — a provincial refund of $1,065.00.
- Total estimated refund: $3,115.00. That's a bit more than $10,000 × 29.65% (the marginal rate at $80,000) would suggest, because the deduction also drops taxable income from $79,073 to $69,073 — crossing the $72,000 Ontario Health Premium threshold and saving a further $150 there.
Worked example — going over your limit
Employment income $50,000 (also used as the prior-year figure), wanting to contribute $12,000, Ontario.
- Room check: 18% × $50,000 = $9,000 — well under the $33,810 cap, so $9,000 is the deduction limit.
- Deductible amount: the lesser of $12,000 and $9,000, so only $9,000 generates a refund this year; the remaining $3,000 isn't deductible until there's new room, though it carries forward automatically.
- Refund on the deductible $9,000: $1,260.00 federal + $604.50 Ontario = $1,864.50.
- Over-contribution tax: the $3,000 excess is $1,000 more than CRA's $2,000 buffer, so — if that $1,000 stays in the account un-withdrawn and un-absorbed by new room — CRA can charge 1% of it, or $10, for every month it remains.
Payroll RRSP vs. a lump-sum contribution
Everything above assumes you contribute on your own and claim the deduction when you file — the refund most people picture. If your RRSP contribution instead comes off your paycheque before tax (a payroll RRSP), your employer reduces the tax withheld from that same paycheque immediately, so the tax saving arrives as higher take-home pay spread across the year rather than as a lump sum at tax time. The total amount saved is identical either way — only the timing changes. To see that version of the same deduction, use the Take-Home Pay Calculator, which has its own RRSP field.
FAQ
How is my RRSP refund calculated?
This calculator runs your employment income through the same federal-and-provincial tax engine as our Take-Home Pay Calculator twice — once as entered, once with your deductible RRSP contribution subtracted from taxable income — and the difference in combined federal-plus-provincial tax is your estimated refund. It is not your contribution multiplied by a single tax rate, because Canada's tax brackets are progressive and a large contribution can span more than one bracket.
Why isn't my refund simply my contribution times my tax bracket?
Because income tax in Canada is progressive — only the portion of your income inside each bracket is taxed at that bracket's rate. An RRSP deduction removes income starting from the top, so if your contribution stays entirely inside your current bracket, contribution times marginal rate is a fair estimate. But a larger contribution can push some of the deducted income into a lower bracket, or past a threshold like Ontario's surtax or Health Premium bands, so part of it is saved at a different rate than your headline marginal rate. This calculator applies the actual brackets and credits to both figures instead of a single multiplication.
What happens if I contribute more than my RRSP deduction limit?
Only the portion up to your deduction limit is deductible this year — the excess isn't lost, it carries forward as room you can use once you're no longer over your limit. CRA also allows up to $2,000 of over-contribution without penalty (the over-contribution buffer), but you can only rely on that buffer if you were 18 or older the year before. Beyond that $2,000 buffer, CRA charges a tax of 1% per month on the amount over the buffer, for every month it stays in the account un-withdrawn and un-absorbed by new room.
Does an RRSP contribution through payroll give me the same refund?
No — a payroll RRSP contribution is deducted from your pay before tax is withheld, so the tax saving already shows up as higher take-home pay throughout the year rather than as a refund when you file. The total tax saved is the same either way; only the timing differs. Our Take-Home Pay Calculator models the payroll version of this same deduction.
Why does the calculator ask for last year's income too?
Your RRSP deduction limit for a given year is generally 18% of your earned income from the previous year, up to that year's dollar limit — $33,810 for 2026. If you leave the prior-year field blank, this calculator assumes it equals the income you entered above, which is a reasonable estimate if your income hasn't changed much, but your real limit also includes any unused room carried forward from earlier years and is reduced by a pension adjustment if you belong to an employer pension plan — neither of which this calculator can see.
Is this the exact refund the CRA will give me?
No — treat it as an estimate. It ignores unused RRSP room carried forward from previous years, employer pension adjustments, and any income sources beyond employment income, all of which change your real deduction limit and refund. Your Notice of Assessment or CRA My Account shows your actual, up-to-date RRSP deduction limit.
This page is general information based on published 2026 CRA rules for RRSP deduction limits and the same federal and provincial payroll tax formulas as our Take-Home Pay Calculator, not tax or financial advice. Your own return may differ — talk to a licensed accountant about your specific situation.