Canadian Variable Rate Mortgage Calculator

Calculate your variable rate mortgage payment, trigger rate, and comparison to the 5-year fixed alternative. Includes trigger rate calculation and how close you are to hitting it, prime rate scenarios showing payments at ±0.5%, ±1%, and ±2%, explanation of static payment versus adjustable payment variable mortgages, Bank of Canada prime rate history from 2015 to 2026, and break penalty comparison showing the variable rate's major exit cost advantage.

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Variable Rate Monthly Payment
CA$2,612/mo
Current rate: 3.90% (Prime 4.7% -0.80%)
5-Year Fixed Monthly
CA$2,979/mo
Monthly Saving vs Fixed
CA$367/mo
Trigger Rate
6.27%
Rate Headroom to Trigger
+2.37%

The trigger rate is the interest rate at which your fixed monthly payment no longer covers the interest charges — meaning none of your payment reduces the principal. If rates rise above the trigger rate, your amortization extends and you may owe more than you originally borrowed (negative amortization).

Trigger Rate Formula:
Trigger Rate = (Monthly Payment ÷ Loan Balance) × 12 × 100

Your figures:
Monthly Payment: CA$2,612
Loan Balance: CA$500,000
Trigger Rate: 6.27%
Current Rate: 3.90%
Rate Headroom: +2.37%
Current Variable Rate
3.90%
Prime 4.7% -0.8%
Trigger Rate
6.27%
Rate where payment covers interest only
Headroom
+2.37%
Rate rise before hitting trigger
Monthly Interest at Trigger
CA$2,612/mo
= your current payment (no principal reduction)
Many Canadian variable-rate mortgage holders hit their trigger rates during the 2022–2023 rate hiking cycle when the BoC raised rates by 4.25% in under 18 months. If you have a static-payment variable mortgage and rates rise above your trigger rate, your lender will typically contact you to increase your payment or make a lump sum payment to restore normal amortization.

The Bank of Canada prime rate from 2015 to 2026. Understanding the historical range helps put current rates in context.

YearBoC Prime RateVariable at Prime -0.8%5yr Fixed ApproxVariable Advantage
20152.70%1.90%3.90%+2.00%
20162.70%1.90%3.90%+2.00%
20173.20%2.40%4.40%+2.00%
20183.95%3.15%5.15%+2.00%
20193.95%3.15%5.15%+2.00%
20202.45%1.65%3.65%+2.00%
20212.45%1.65%3.65%+2.00%
20226.45%5.65%7.65%+2.00%
20237.20%6.40%8.40%+2.00%
20245.45%4.65%6.65%+2.00%
20254.95%4.15%6.15%+2.00%
2026 (now)4.70%3.90%5.90%+2.00%
Context: The BoC rate cycle 2022–2023 was the most aggressive in Canadian history — rates rose from 0.25% to 5.00% in 18 months. Before this, prime held below 4% for nearly a decade. Current rates in 2026 have moderated as the BoC cut rates through 2024–2025. The variable rate environment is now more attractive again.

How to Use This Canadian Variable Rate Mortgage Calculator

Enter your loan amount, prime rate discount or premium (e.g. −0.80 for prime minus 0.80%), amortization period, and the 5-year fixed rate you have been offered for comparison. The calculator shows your current variable rate payment, your trigger rate, the rate headroom before the trigger is hit, and a comparison with the 5-year fixed alternative.

What is a Canadian Variable Rate Mortgage?

A variable rate mortgage in Canada has an interest rate that fluctuates with the Bank of Canada (BoC) prime rate. When the BoC raises or lowers its overnight rate, major bank prime rates follow, and your variable mortgage rate changes accordingly. Variable rates are typically quoted as "prime minus X%" — for example, prime − 0.80% means your rate is 0.80% below the bank's prime lending rate at any given time.

The Trigger Rate Explained

Trigger Rate Formula:
Trigger Rate = (Monthly Payment ÷ Loan Balance) × 12 × 100

Example:
Loan: $500,000 | Amortization: 25yr | Rate: 3.90%
Monthly Payment: $2,600/mo
Trigger Rate = ($2,600 ÷ $500,000) × 12 × 100 = 6.24%

If prime rises to 7.04% (prime − 0.80% = 6.24%):
→ Your payment covers interest only — no principal reduction
→ If rates rise further: negative amortization begins
→ Lender will require payment increase or lump sum

The trigger rate is particularly relevant for static-payment variable rate mortgages (VRM), where your payment stays the same as rates change. For adjustable-payment mortgages (ARM), there is no trigger rate because the payment adjusts immediately when the prime rate changes.

Static Payment vs Adjustable Payment Variable Mortgages

Canadian variable rate mortgages come in two fundamentally different structures:

During the 2022–2023 rate hiking cycle, many Canadians with static-payment VRMs hit their trigger rates as prime rose from 2.45% to 7.20% in 18 months. This caused significant payment shock as lenders required immediate payment increases.

Example: $500,000 Variable Rate Mortgage

Priya takes a variable rate mortgage in Toronto

Priya borrows $500,000 at prime − 0.80%. Current prime is 4.70%, so her rate is 3.90% and her monthly payment on a 25-year amortization is $2,600.

Loan Amount$500,000
Rate3.90% (prime 4.70% − 0.80%)
Monthly Payment (25yr)$2,600/mo
5-Year Fixed Alternative$2,740/mo at 5.19%
Monthly Saving vs Fixed$140/mo = $1,680/yr
Trigger Rate6.24% (prime needs to reach 7.04%)
Variable Break Penalty~$5,850 (3-month interest)
Fixed Break Penalty (est.)$12,000–$25,000+ (IRD)

Priya saves $140 per month versus a 5-year fixed rate. Her trigger rate requires prime to rise another 2.34% before hitting. And if she needs to break her mortgage early, her variable penalty is a fraction of what a fixed mortgage would cost.

Frequently Asked Questions

The trigger rate is the interest rate at which your fixed monthly payment no longer covers the interest portion of your mortgage — meaning no principal is being repaid. On a static-payment VRM, if rates rise above the trigger rate, negative amortization begins and you owe more than you originally borrowed. Your lender will require you to increase your payment or make a lump sum prepayment to restore normal amortization. The trigger rate is calculated as: (monthly payment ÷ loan balance) × 12 × 100.
The Bank of Canada sets the overnight lending rate, which directly influences the prime lending rates used by major Canadian banks. When the BoC raises or lowers its rate, bank prime rates follow within days. Variable rate mortgages are typically priced at prime minus a discount (e.g. prime − 0.80%). The current prime rate is approximately 4.70% as of early 2026, having fallen from a peak of 7.20% in 2023 following BoC rate cuts through 2024–2025.
Historically, variable rate mortgages in Canada have outperformed 5-year fixed rates in approximately 80% of rolling 5-year periods. Variable rates start lower and borrowers benefit immediately. However, the 2022–2023 rate cycle proved that rapid rate hikes can make fixed mortgages advantageous in specific periods. If rates are expected to fall, variable wins clearly. If significant rate rises are expected, fixed provides certainty. Most economists recommend variable for long-term borrowers who can tolerate short-term rate volatility.
The penalty for breaking a variable rate mortgage in Canada is only 3 months of interest on the outstanding balance — one of the lowest possible penalties. On a $500,000 mortgage at 3.90%, this is approximately $4,875. Breaking a 5-year fixed mortgage uses the Interest Rate Differential (IRD) calculation, which compares your contracted rate to the current rate for the remaining term. When rates have fallen significantly since you locked in, the IRD penalty can reach $20,000–$60,000 or more. This penalty asymmetry is a major, often underweighted advantage of variable rate mortgages.
An Adjustable Rate Mortgage (ARM) changes your monthly payment immediately when prime rates change — your amortization stays on schedule but your payment goes up or down. A Variable Rate Mortgage (VRM) keeps your payment fixed but changes how much goes to interest versus principal — the amortization can extend or shorten. VRMs have trigger rate risk; ARMs do not. When choosing variable, clarify with your lender which type you are taking.

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