HELOC Calculator Canada — How Much Can You Access?

The 65% and 80% limits: consumer rule vs. regulatory source

FCAC states the consumer-facing version plainly: “You may borrow up to 65% of your home's value” on a standalone HELOC, and “may usually borrow up to 80% of your home's value” when the HELOC is combined with a first mortgage. The regulatory source behind the 65% figure is OSFI's Guideline B-20, which caps the non-amortizing (revolving) component of a HELOC at a maximum 65% LTV. FCAC frames the 80% combined figure with the word “usually” rather than as an absolute regulatory ceiling — B-20's 65% cap applies specifically to the revolving portion, and the combined 80% is how the industry structures a readvanceable mortgage's fixed-plus-revolving components under that constraint, not a single explicit “80%” sentence in B-20 itself.

Worked example: on a C$780,000 home with no existing mortgage, a standalone HELOC caps at 65% × C$780,000 = C$507,000. If instead C$300,000 of that value is already carrying a first mortgage in a readvanceable structure, the combined ceiling is 80% × C$780,000 = C$624,000, leaving C$324,000 of available revolving room (C$624,000 − C$300,000) — subject to the separate 65%-of-value cap on the revolving piece itself, which in this case is well above that C$324,000 figure and so isn't the binding constraint.

Qualifying for a HELOC: the same stress test as a mortgage

A HELOC is an uninsured credit product secured against your home, and OSFI's B-20 guideline states the qualifying rate for all uninsured mortgages — which includes the revolving HELOC component — must be the greater of the contract rate plus a Superintendent-set buffer, or a Superintendent-set floor. The current numbers behind that rule are the contract rate plus 2%, or 5.25%, whichever is higher. That means the lender qualifies you on your ability to carry the HELOC at this higher stress-tested rate, not at the actual prime-plus-spread rate you'll be charged — the same mechanism that qualifies a mortgage applicant, applied to the credit line.

This matters most at the margin: a household that qualifies comfortably for a mortgage payment at their contract rate can still be declined HELOC room, or approved for less than the 65%/80% ceiling, if adding the stress-tested carrying cost of the HELOC on top of their existing mortgage payment pushes their debt ratios too high.

HELOC vs. cash-out refinance above 80% loan-to-value

A HELOC cannot exceed the 65%/80% ceilings above — there's no insured version of a HELOC that lets you borrow past them. A cash-out mortgage refinance can go further, but only by switching to an insured mortgage. CMHC's own minimum-down-payment structure caps insurability at a purchase price below C$1,500,000, and its premium schedule runs from 0.60% of the loan at up to 65% LTV to 4.00% at 90.01–95% LTV — a cost a HELOC never carries, since a HELOC is uninsured and capped well below the LTV bands where CMHC premiums apply. An amortization period beyond 25 years on that insured refinance adds a further 0.20% surcharge on the premium. In practice: staying inside the 65%/80% HELOC ceilings avoids CMHC premiums entirely; pulling more equity than that requires either an insured refinance (with the premium schedule above) or a second mortgage, not a bigger HELOC.

Why the 65% cap applies to the revolving piece, not the whole mortgage

A readvanceable mortgage bundles two different credit structures under one product: a fixed, amortizing mortgage portion that pays down on a schedule, and a revolving HELOC portion that doesn't. OSFI's B-20 cap of 65% LTV on the non-amortizing component exists because a revolving balance that never has to shrink carries different risk than a mortgage balance that's contractually required to. As your fixed mortgage portion pays down, more room can open up inside the readvanceable structure's revolving limit — which is why some readvanceable products advertise credit that automatically grows as you pay down principal, without ever exceeding either the 65% revolving cap or the 80% combined ceiling.

This distinction also explains why a HELOC and a mortgage renew on different logic. FCAC defines a mortgage term as the contract period that resets periodically while amortization continues underneath it; a HELOC has no amortization schedule at all to reset — it's assessed for renewal on the credit line itself, and your available room can be recalculated any time your home's appraised value or your outstanding mortgage balance changes.

HELOC rates float with prime, not with a fixed contract rate

A mortgage's rate is locked for the term; a HELOC's rate is not — it's priced as prime plus a lender-set spread and moves every time the chartered-bank prime rate changes. The Bank of Canada's own data shows chartered-bank prime at 4.45% across the three most recent weekly observations available, and notes explicitly that each financial institution sets its own prime rate as a function of its funding costs, which is in turn influenced by — not mechanically derived from — the Bank of Canada's policy rate. That means the interest-only payment on a fully drawn HELOC changes whenever prime moves, with no renewal notice or new contract required, unlike the fixed rate on the mortgage portion beside it in a readvanceable structure.

Worked example: how a HELOC payment affects your qualifying ratios

CMHC's insured-mortgage qualifying rule requires that 50% of monthly condominium fees be included in both the gross debt service (GDS) and total debt service (TDS) ratio calculations — a detail that matters directly for a condo owner adding HELOC carrying costs on top. Take a hypothetical household with C$9,500 gross monthly income, an existing mortgage payment of C$2,600, condo fees of C$500 (of which 50%, or C$250, counts toward the ratios per CMHC's rule), and a newly drawn HELOC carrying an interest-only payment of C$310/month at the stress-tested qualifying rate.

The 39% GDS ceiling above is CMHC's, not an OSFI rule for HELOCs

The worked example above uses CMHC's 39% GDS ceiling because it's a published, citable number — but a HELOC is an uninsured product, and OSFI's own B-20 guideline does not itself prescribe a fixed numeric GDS or TDS ceiling for uninsured lending. Instead, OSFI expects each federally regulated institution to set and hold to its own maximum ratios. In practice that means your actual lender's GDS/TDS cutoff for HELOC approval can sit above or below 39%/44% — the worked example is a reasonable stand-in for modelling, not a guarantee of your specific lender's policy. Ask your lender for its stated maximum before treating 39% as a hard line.