When you are buying a home or refinancing your mortgage, one of the most important decisions you will make is choosing the right type of mortgage. In Canada, most homebuyers are familiar with fixed-rate mortgages — but another option that offers flexibility and potential savings is the adjustable-rate mortgage (ARM).
An adjustable-rate mortgage (ARM) — also known in Canada as a variable-rate mortgage or floating-rate mortgage — is a home loan where the interest rate changes periodically based on market conditions.
Unlike a fixed-rate mortgage, which locks in the same interest rate for the entire term, an adjustable-rate mortgage’s interest rate can rise or fall over time. This means your monthly payments may increase or decrease depending on how the market moves.
How an Adjustable-Rate Mortgage Works
When you get an adjustable-rate mortgage, your loan is tied to a benchmark rate (often called the prime Rate), which is influenced by the Bank of Canada’s overnight Rate. Lenders then add a margin — a fixed percentage that doesn’t change — to determine your total mortgage rate.
When the Bank of Canada adjusts its overnight lending rate, the prime rate typically moves in the same direction, and your mortgage rate adjusts accordingly.
Key Components of an Adjustable-Rate Mortgage
To understand ARMs more clearly, it helps to know the main components that determine how they function:
1. Initial Rate Period
This is the starting interest rate you pay for an introductory period (for example, the first 6 months or a year). It’s usually lower than the fixed-rate mortgage rate, making ARMs attractive to new borrowers.
2. Adjustment Period
After the initial period ends, your rate adjusts at set intervals — for instance, every six months or once a year — depending on your mortgage agreement.
3. Index (Benchmark Rate)
The Rate is linked to a benchmark, such as the Bank of Canada prime Rate or another reference rate used by your lender. When this index changes, your interest rate changes.
4. Margin
The lender adds a fixed margin to the benchmark rate to determine your total interest rate. The margin depends on your credit score, down payment, and overall financial profile.
5. Interest Rate Caps
Many adjustable-rate mortgages come with caps — limits on how much your interest rate can rise or fall during each adjustment and over the lifetime of your loan. This helps protect borrowers from drastic rate increases.
For example:
- Periodic Cap: Limits how much the Rate can increase at one adjustment (e.g., no more than 1%).
- Lifetime Cap: Limits how much the Rate can increase overall (e.g., no more than 5% above the starting rate).
Adjustable-Rate Mortgage vs. Variable-Rate Mortgage
In Canada, the terms adjustable-rate mortgage and variable-rate mortgage are often used interchangeably, but there’s a subtle difference:
| Feature | Adjustable-Rate Mortgage (ARM) | Variable-Rate Mortgage (VRM) |
| Payment Changes | Monthly payments change as rates change | Monthly payment stays the same, but the interest-to-principal ratio changes |
| Rate Adjustment | Rate adjusts automatically based on prime rate | Rate adjusts, but payments may stay fixed |
| Interest Savings | Can save more if rates drop | May take longer to pay off principal when rates rise |
| Best For | Borrowers who can handle fluctuating payments | Borrowers who want payment stability but still want rate flexibility |
Pros of an Adjustable-Rate Mortgage
An adjustable-rate mortgage can offer several benefits — especially when interest rates are stable or trending downward.
1. Lower Initial Interest Rates
ARMs often start with lower interest rates than fixed-rate mortgages, allowing buyers to qualify for larger loans or enjoy smaller monthly payments early on.
2. Potential Savings Over Time
If the prime rate decreases, your mortgage payments could drop, saving you thousands of dollars over your mortgage term.
3. Flexibility for Short-Term Homeowners
If you plan to sell or refinance within a few years, an ARM can make sense since you will benefit from lower rates during the initial period before any major adjustments occur.
4. Faster Mortgage Payoff (in Some Cases)
When rates are low, a larger portion of your payment goes toward the principal, helping you build home equity faster.
Cons of an Adjustable-Rate Mortgage
While ARMs can be financially rewarding, they also come with risks — mainly due to fluctuating rates.
1. Payment Uncertainty
Because rates can change, your monthly payment might increase unexpectedly, making budgeting more difficult.
2. Higher Long-Term Costs
If interest rates rise significantly, you could pay more than you would with a fixed-rate mortgage.
3. Potential Stress Test Implications
In Canada, borrowers must qualify for an ARM using the higher of the contract rate or the Bank of Canada’s stress test rate (currently 5.25% or the contract rate + 2%). Rising rates could make it harder to qualify for renewals or refinancing.
4. Not Ideal for Risk-Averse Borrowers
If you prefer predictable payments and peace of mind, an adjustable-rate mortgage may cause financial stress due to its variability.
When an Adjustable-Rate Mortgage Might Be a Good Idea
An ARM can be an excellent option for specific borrowers. You might consider one if:
- You expect interest rates to stay stable or fall.
- You plan to sell or refinance before the adjustable period begins.
- You have enough financial flexibility to handle potential rate increases.
- You want to take advantage of low introductory rates to reduce initial payments.
Example:
If you are a first-time homebuyer planning to upgrade within five years, choosing an adjustable-rate mortgage could help you save money during those early years.
Example: How an Adjustable-Rate Mortgage Works in Practice
Let us say you take out a $500,000 mortgage with:
- A 5-year adjustable rate
- A starting rate of 5.00%
- The Rate is tied to the prime Rate, which is currently 6.70%
- A margin of -1.70%
If the prime Rate drops by 0.25%, your new Rate becomes 4.75%, and your monthly payments will decrease.
However, if the prime Rate rises to 7.20%, your new Rate becomes 5.50%, meaning your payments will increase accordingly.
How to Decide Between a Fixed and Adjustable-Rate Mortgage
Here is a quick comparison to help you decide:
| Factor | Fixed-Rate Mortgage | Adjustable-Rate Mortgage |
| Rate Stability | Stays the same | Changes with market |
| Monthly Payments | Predictable | Can increase or decrease |
| Initial Interest Rate | Slightly higher | Usually lower |
| Best For | Long-term homeowners, stable budgets | Short-term homeowners, flexible budgets |
| Risk Level | Low | Moderate to high |
If stability and long-term predictability matter most, go fixed. If you are comfortable with some risk and want short-term savings, an adjustable-rate mortgage could be your best bet.
Tips for Managing an Adjustable-Rate Mortgage
If you decide to choose an ARM, here are some innovative strategies to manage your mortgage effectively:
1. Build a Financial Cushion
Set aside an emergency fund to cover potential payment increases when rates rise.
2. Monitor Interest Rate Trends
Stay informed about the Bank of Canada’s policy changes and global economic trends that may influence rates.
3. Consider Early Payments
Pay extra toward your principal when rates are low. This reduces your total interest over time.
4. Know Your Caps and Terms
Understand your mortgage’s rate caps, adjustment frequency, and maximum potential payment increase before signing.
5. Refinance When Appropriate
If rates begin rising sharply, consider refinancing into a fixed-rate mortgage to lock in a stable rate.
The Role of the Bank of Canada
The Bank of Canada (BoC) plays a significant role in determining how adjustable-rate mortgages perform. The BoC’s key interest rate influences the prime rate, which lenders use as the base for most variable and adjustable mortgages.
When the BoC raises its Rate to control inflation, the cost of borrowing increases — including for ARM borrowers. When the rate is cut, mortgage holders can benefit from lower payments.
Final Thoughts: Is an Adjustable-Rate Mortgage Right for You?
An adjustable-rate mortgage can be an innovative financial tool when used strategically. It offers lower initial rates, flexibility, and potential savings — especially in stable or declining rate environments.
However, it also carries risk. If rates rise significantly, your payments could increase, impacting your budget.
Before choosing an ARM, consider your:
- Financial stability
- Homeownership timeline
- Risk tolerance
- Long-term goals
If you are uncertain, working with a mortgage broker or financial advisor can help you evaluate your options and find the right fit for your situation.
Contact us for more information.