Continue your simulation by testing a BMO fixed vs variable personal loan against five possible paths for the Canadian prime lending rate.
Choosing between fixed and variable is really a bet on the future, and nobody can predict prime with certainty. Scenario planning turns that bet into a set of outcomes you can live with. This guide models a C$20,000 loan under five prime paths, shows the payments and total interest in each and explains how to choose without guessing.
Direct answer: a fixed BMO rate suits borrowers whose budgets cannot absorb higher payments, while a variable rate suits borrowers who could handle a rise and value the chance of paying less. If a variable loan starts one point below the fixed option, prime generally needs to climb by about two points before the variable choice costs more overall.
In Canada, variable personal lending is usually priced as prime plus a margin, and prime tends to follow the Bank of Canada policy rate. BMO sets both the fixed rate and the variable margin individually, based on your credit, the amount and the term. The figures in this guide are illustrations, not quotes from the bank.
A typical error is comparing today’s variable rate with today’s fixed rate and stopping there. The real question is what happens across the entire repayment term. A small discount at the start can disappear after one or two increases, while a fixed rate protects you from that risk at a known price agreed right at the beginning.
Next, you will find the five scenarios in a table, a break-even explanation, a budget stress test, how to read your offer, a decision checklist, a look at prepayment and refinancing and frequent questions. Keep your monthly budget and a sense of how much variation you could tolerate before reading through the detailed scenarios.
The setup
Marc, a paramedic in Halifax, wants C$20,000 over five years to consolidate two high-rate cards. He is offered an illustrative fixed rate of 9.5% or a variable rate starting at 8.5%. He models what happens if the variable rate changes by a set amount after two years and stays there.
Five scenarios
| Scenario after year two | Payment years 1-2 | Payment years 3-5 | Total interest |
|---|---|---|---|
| Fixed at 9.5% | about C$420 | about C$420 | about C$5,200 |
| Variable falls 1 point | about C$410 | about C$404 | about C$4,400 |
| Variable holds | about C$410 | about C$410 | about C$4,620 |
| Variable rises 1 point | about C$410 | about C$416 | about C$4,840 |
| Variable rises 2 points | about C$410 | about C$422 | about C$5,060 |
| Variable rises 3 points | about C$410 | about C$429 | about C$5,280 |
Variable stays cheaper unless the rate rises by about three points after year two. Even then, the extra cost is modest, around C$80. The payment difference is only a few dollars a month at this loan size, which shows that certainty is the main benefit of fixing.
Finding the break-even
The break-even is the rise that makes both options cost the same. In Marc’s case it sits just under three points after year two. If the rise came earlier, the break-even would be lower, because the higher rate would apply to a larger balance for longer. Earlier changes matter more than later ones.
A budget stress test
- Write down your maximum comfortable payment.
- Calculate the variable payment if prime rose two points tomorrow.
- Check that it stays under your maximum with a buffer.
- If it does not, choose fixed or borrow less.
- Repeat the test whenever prime moves.
Marc’s maximum was C$450. Even the worst scenario left him C$21 below it, so he felt comfortable choosing variable while keeping a small emergency fund.
The maths behind each row
Each payment uses P·r/(1−(1+r)^−n). For the variable scenarios, the balance after twenty-four payments becomes the new P, the new monthly rate becomes r and the remaining thirty-six months become n. That is how lenders recalculate payments when a variable rate changes.
Reading your BMO offer
- Is the rate fixed, or prime plus a stated margin?
- What is the current prime rate used?
- How and when does the payment change if prime moves?
- Can you switch from variable to fixed later, and at what cost?
- Are prepayments allowed without a charge?
Prepayment and refinancing
Variable loans often allow extra payments with fewer restrictions, which helps if you expect a bonus. Fixed loans may limit prepayments or charge for early payoff. If you might refinance or repay early, ask about these terms before choosing, because they can outweigh small differences in rate.
What if the rise comes early?
Marc also tested a harsher path: a two-point rise after only six months. Because the higher rate would apply to a larger balance for longer, the variable option ended up roughly C$380 more expensive than fixing. That test reminded him that timing matters as much as size, and that early increases are the main risk of choosing variable.
To protect himself, Marc decided to pay an extra C$50 a month while rates stayed flat. Building that habit early would shorten the loan and reduce the balance exposed to any later rise, giving him some of the security of a fixed rate without giving up flexibility.
Fixed rate as insurance
Think of the fixed premium as an insurance cost. In Marc’s case, fixing costs about C$580 more than the variable option if prime holds steady. That is the price of knowing the payment will never move. Some borrowers value that certainty highly, especially when other bills are already tight.
- Insurance value is high when your budget has little slack.
- It is lower when you can absorb rises and plan to prepay.
- Revisit the choice if your income or expenses change.
Decision checklist
- Choose fixed if a two-point rise would strain your budget.
- Choose variable if you can absorb a rise and value flexibility.
- Prefer the option with friendlier prepayment terms if you plan to repay early.
- Compare total interest across several scenarios, not just today’s rate.
Marc kept his scenario table in a note on his phone. Each time the Bank of Canada announced a decision, he updated the variable row and checked that the payment still sat below his ceiling.
Summary: plan for several futures
Scenario planning shows how fixed and variable options behave as prime moves, so you can choose based on your budget rather than a forecast.
- Model falls, holds and rises in prime.
- Find the break-even rise.
- Stress test your budget.
- Check prepayment and switching terms.
- Rerun the scenarios when prime changes.
Frequently asked questions
Does BMO publish its prime rate?
Canadian banks publish their prime rates, which usually move after Bank of Canada announcements.
Can a variable payment change immediately?
Changes typically take effect after the bank adjusts prime, so read how your agreement handles timing.
Is fixed always more expensive?
Not if rates rise enough, which is why fixed acts like insurance.
What margin should I expect?
Margins depend on your profile, so ask BMO for a written quote.
Can I fix my rate later?
Some lenders allow a switch, sometimes with conditions or fees, so ask BMO how it handles conversions.
How often should I rerun the scenarios?
Whenever prime changes or your budget shifts, because both alter the outcome of each path.
Does the term change the break-even?
Yes, longer terms leave more time for rate changes, which makes the break-even rise smaller.
Conclusion
Weighing a BMO fixed vs variable personal loan is easier with scenarios than with predictions. Model several prime paths, find your break-even, stress test your budget and confirm the actual rate, margin and prepayment terms with Bank of Montreal before choosing.