How Do Variable Mortgage Rates Work in Alberta?
Short answer
A variable mortgage rate is tied to the lender's prime rate plus or minus a fixed spread for your term. When prime moves — usually after Bank of Canada policy changes — your interest rate adjusts. Your payment may stay the same while more goes to interest, or your payment may increase, depending on the product. Some products hit a trigger rate before payments change.
The plain-English version
Variable-rate mortgages in Canada are typically quoted as "prime minus" or "prime plus" a spread. If prime is 6.45% and your rate is prime minus 0.85%, your contract rate is 5.60%. The spread is locked for your term; only prime fluctuates. Payments are calculated using monthly compounding even though the rate tracks a prime that responds to policy rate changes.
There are two main payment designs. On a standard variable-rate mortgage (VRM), your payment stays fixed but the interest/principal split shifts as rates move — if rates rise enough, you may hit a trigger rate. On an adjustable-rate mortgage (ARM), the payment itself changes when prime moves. Product labels vary by lender, so read your commitment letter carefully.
Alberta-specific considerations
- Alberta variable borrowers qualify under the federal stress test at the higher of contract rate plus 2% or the benchmark qualifying rate (5.25% floor) — a rising prime during your term does not re-trigger qualification.
- Households with tight budgets in higher-priced Calgary or Edmonton markets should model payment increases, not just the starting rate.
- Many Alberta lenders offer conversion from variable to fixed mid-term — terms and conversion rates differ, so confirm before you sign.
Example scenario
You take a $380,000 variable mortgage at prime minus 0.90% when prime is 6.45%, giving a 5.55% contract rate. Payment is about $2,310/month on 25-year amortization. If prime rises 0.75% over a year, your rate becomes 6.30%. On a fixed-payment VRM, more of that $2,310 goes to interest and less to principal — your amortization effectively lengthens until you hit the trigger rate.
Common mistakes to avoid
- Assuming "variable" always means your payment goes up when prime rises — many VRMs keep payments level initially.
- Not asking whether your product is a VRM or ARM before signing.
- Choosing variable only for the lowest starting rate without stress-testing +1% or +2% scenarios.
- Forgetting the spread is fixed but prime is not — there is no cap on how high prime can go during your term.