CMHC Insurance Calculator

What the CMHC Insurance Calculator does

Any Canadian mortgage with less than 20% down requires default insurance — commonly called CMHC, though Sagen and Canada Guaranty offer the same product on a near-identical premium schedule. This calculator computes the exact premium your loan-to-value places you in, the provincial sales tax that applies on top of it, and what financing that premium actually costs you every month over the full amortization.

It also shows the premium at 5%, 10%, 15% and 20% down side by side on the same purchase price, so the exact dollar value of moving up a tier — or clearing the insurance requirement entirely — is visible before you decide how much to put down.

• Your exact premium rate, by loan-to-value band
• The dollar premium, and the provincial sales tax due on it in cash
• The total mortgage amount once the premium is added
• The monthly payment impact of financing the premium, not just the lump sum
• Premium, PST and interest combined — the true lifetime cost of insuring the mortgage

The variables that move the answer — and how lenders treat them

The premium is driven almost entirely by loan-to-value, with specific surcharges layered on top for higher-risk structures.

• Loan-to-value — the single input the base premium rate is looked up against. Crossing from one band into another changes the rate applied to your ENTIRE loan, not just the portion above the threshold. That makes a down payment sitting just below a band boundary worth checking carefully: a few thousand dollars more down can cut the rate on the whole loan.
• Amortization — a 30-year amortization adds a surcharge on top of the standard rate, because the insurer’s exposure stays outstanding for longer before the loan is paid down.
• Down payment source — borrowed funds are treated as non-traditional and carry an additional surcharge, reflecting the extra leverage already present before the mortgage is even considered.
• Purchase price — above the insured price cap the mortgage is not insurable at any down payment below 20%. There is no partial premium above the cap; the requirement simply becomes a hard 20% minimum.
• Province — Ontario, Quebec and Saskatchewan apply provincial sales tax directly to the premium. It is calculated the same way whether or not the premium itself is financed, and it is never eligible to be added to the mortgage.

How the premium is actually calculated in Canada

The loan is the purchase price minus the down payment, and loan-to-value is that loan divided by the price. If LTV is 80% or less the premium is zero. Otherwise the base rate is looked up from a table of LTV bands — each band from 80% up to 95% carries a progressively higher rate, since a smaller down payment is more risk to the insurer.

Surcharges are added to the base rate, not applied separately: a 30-year amortization and a non-traditional down payment source each add a fixed number of percentage points on top of the base LTV rate. The total rate is then applied to the full loan — premium = loan × total rate — and the provincial sales tax, where it applies, is calculated on the premium itself, not on the loan.

The premium is usually added to the mortgage principal rather than paid in cash, so the total mortgage becomes loan plus premium, and the payment is recalculated on that larger amount using the same semi-annual compounding used everywhere else in Canadian mortgage math. The PST is never eligible to be capitalised — it is a cash requirement at closing regardless of what happens to the premium.

• LTV = loan ÷ price; premium is zero if LTV ≤ 80%
• Base rate by LTV band, plus 0.20% for a 30-year amortization, plus 0.15% for a borrowed down payment
• Premium ($) = loan × total rate
• PST = premium × provincial rate — cash only, never financeable

How lenders use these numbers to qualify you

The premium is not a side calculation. It flows straight into the mortgage amount a lender registers, and from there into every other number in the file.

• Premium rate and amount — added directly to the loan to produce the true mortgage amount, which is what your payment, your qualifying ratios and your stress test are all calculated against.
• PST on the premium — not part of the mortgage at all. It is a closing-day cash requirement sitting alongside land transfer tax and legal fees, and it is the line item first-time buyers most often forget to budget for.
• Monthly payment impact — the premium’s effect on GDS and TDS runs through this figure, since a larger financed principal produces a larger qualifying payment and uses up debt service room like any other cost.
• Interest on the premium — not underwritten against directly, but it is the clearest case for stretching toward 20% down if the timeline allows.

Using your results well

Compare your current tier against the next one up, and against 20%, in the tier table. The dollar gap to the next band is often smaller than people expect, and the premium saved by clearing it is usually a meaningful multiple of that gap — because the better rate applies to the whole loan, not just the extra down payment.

What this calculator does not do is confirm your insurer’s schedule at the moment you close, or price the separate schedule used for self-employed applicants without third-party verified income. Premium schedules are set by the insurers and reviewed periodically — treat these as the standard schedule and confirm exact numbers with your lender or broker before relying on them for a closing budget.

• Compare your tier against the next one up before finalising your down payment
• Budget the PST separately — it is cash, due at closing, and never financeable
• If self-employed without verified income, confirm your specific schedule with a broker
• Weigh the lifetime cost against how long it would take to save a larger down payment
• Treat this as an estimate and confirm the current schedule before closing