RRSP or TFSA? The answer depends on two rates, not one.
Every other calculator compares your tax rate now against your tax rate in retirement. That misses the two things most likely to flip the answer for a real Canadian household: the Canada Child Benefit you gain on the way in, and the Guaranteed Income Supplement you lose on the way out. This one counts both.
For your situation
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Rate going in
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Rate coming out
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RRSP route$—
RRSP after tax and any clawback$—
Tax refund, invested$—
Extra CCB, invested$—
TFSA route$—
Difference$—
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The rule, stated properly
The textbook version of this decision is "RRSP if your tax rate is higher now than in retirement, TFSA otherwise." That is correct as far as it goes, and it goes about half as far as it should.
The RRSP is a deferral: you skip tax at today's rate and pay it at your future rate. So the whole question is which rate is higher. But "rate" should mean every dollar the government gives or takes as a consequence of that contribution — not just income tax:
rate going in = marginal tax rate + CCB increase per dollar deducted
rate coming out = retirement tax rate + GIS reduction per dollar withdrawn
RRSP wins when: rate going in > rate coming out
Written that way, both of the usual mistakes become obvious. A parent in the Canada Child Benefit's steep band has a rate going in that is 7 to 23 points higher than their tax rate alone — the RRSP is better than they think. A lower-income saver who will receive the Guaranteed Income Supplement has a rate coming out that is 50 to 75 points higher than their tax rate — the RRSP may be far worse than they think, and the TFSA is often the correct retirement account.
Both effects are large enough to reverse the decision outright. Neither appears in a standard RRSP-vs-TFSA calculator.
Why the arithmetic is simpler than it looks
Assume you contribute the same amount either way and invest the refund. Over n years at return r:
TFSA route = C × (1+r)ⁿ
RRSP route = C × (1+r)ⁿ × (1 − rate out + rate in)
The growth term is identical and cancels. What remains is a single comparison of two rates — which is why the length of time invested and the rate of return, the two inputs people agonise over most, do not change the winner at all. They change the size of the prize, not who wins it.
The one input that does change the winner, beyond the rates themselves, is whether you actually invest the refund. If you spend it, the RRSP's advantage largely disappears, because the comparison becomes an after-tax RRSP withdrawal against a full TFSA balance. This is not a hypothetical failure mode — it is the ordinary one. Toggle it above and watch the answer move.
Three situations where the standard advice is wrong
The parent in the CCB's steep band
Two children, family net income between $38,237 and $82,847, a 30% marginal rate. Tax rates alone might suggest the accounts are close to a tie. Add 13.5 points of CCB increase and the rate going in becomes 43.5% against a retirement rate around 25% — the RRSP wins clearly. With three children it is 49% going in. Details are in the CCB calculator.
The modest earner who will receive GIS
A 22% marginal rate today, and a retirement of OAS, a small CPP and GIS. The textbook says RRSP, because 22% now beats a low retirement tax rate. But GIS claws back roughly 50 cents per dollar withdrawn, so the true rate coming out is over 50% against 22% going in. The TFSA is the right account by a wide margin, and it is not close. See the GIS guide.
The high earner in a peak year
A 48% marginal rate now, expecting perhaps 30% in retirement. This is the textbook RRSP case and it holds: 18 points of spread on a large contribution, compounding untaxed for decades. No adjustment needed — just make sure the refund gets invested rather than absorbed.
2026 limits and deadlines
| RRSP | TFSA |
|---|
| 2026 limit | 18% of prior-year earned income, to $33,810 | $7,000 |
| 2025 limit | to $32,490 | $7,000 |
| Unused room | Carries forward | Carries forward indefinitely |
| Deadline | First 60 days of the following year | None |
| Contribution deductible | Yes | No |
| Withdrawals taxed | Yes, in full | No |
| Withdrawal restores room | No | Yes, the following January |
| Counts against OAS / GIS | Yes | No |
RRSP room is reduced by your pension adjustment if you have a workplace pension, and both accounts allow a $2,000 lifetime overcontribution buffer in the RRSP's case — the TFSA has none, and charges 1% a month on any excess. Full TFSA mechanics are in the TFSA guide; what eventually happens to RRSP money is in the RRIF guide.
RRSP vs TFSA questions, answered
What's the short answer?
RRSP if your total rate going in — marginal tax plus any CCB increase — is higher than your total rate coming out — retirement tax plus any GIS clawback. TFSA otherwise. Comparing tax rates alone misses the two factors most likely to flip it.
Does having children change it?
Yes, a lot. An RRSP deduction lowers net income, which raises next year's Canada Child Benefit by 7% to 23% of the contribution. For families in the steep band that often makes the RRSP the clear winner.
Why might an RRSP be wrong for a lower earner?
Because RRSP and RRIF withdrawals reduce the Guaranteed Income Supplement by roughly 50 to 75 cents on the dollar for a single person, on top of income tax. TFSA withdrawals are invisible to that test.
What if I spend the refund?
The RRSP's edge mostly disappears — this is the most common reason RRSPs underperform in real life. Model it with the toggle above.
What about an employer match?
It beats both. An employer matching your group RRSP contribution is an immediate 50% or 100% return that no tax argument competes with. Capture the full match first, then apply this decision to whatever is left.
Can I do both?
Yes, and most people should. The comparison here is about where the marginal dollar goes, not an all-or-nothing choice. A common order: capture the employer match, then fill whichever account this calculator favours, then the other.
What about the FHSA?
If you're saving for a first home it beats both — deductible going in like an RRSP, tax-free coming out like a TFSA, with nothing to repay. See the FHSA calculator.
Method and sources
Both routes contribute the same amount and grow at the same rate for the same period, so the compounding term cancels and the result turns on the two combined rates. The RRSP route is valued as the balance net of retirement tax and any GIS reduction, plus the tax refund and CCB increase invested in a TFSA at the same return. The CCB increase uses the marginal reduction rate at your family net income and number of children for the July 2026 – June 2027 benefit year, applied for one benefit year. The GIS setting applies a flat 50% clawback for "likely" and 25% for "possibly" — real GIS rates run from 25% to 75% depending on marital status and income band, so treat this as a directional adjustment and check the GIS calculator for your own figure.
Simplifications worth knowing: marginal rates are treated as flat rather than as brackets, the refund is assumed received and invested in one lump, provincial benefit programs are not modelled, and no allowance is made for the age-65 pension income credit or income splitting, both of which modestly favour the RRSP.
Limits from CRA — MP, DB, RRSP, DPSP, ALDA, TFSA limits and the YMPE. CCB parameters from CRA — how we calculate your CCB.
Related: CCB calculator · RRSP contribution limit · GIS calculator · TFSA room · RRIF withdrawals · FHSA calculator
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