If you signed a fixed rate in 2023, there's a fair chance you're paying a rate that starts with a five while new five-year terms start with a three. Breaking costs a penalty. Waiting costs two more years at the old rate. Somewhere between the two is a third option that lenders mention less often than you might expect: the blend and extend.
This explains what it is, how the blended rate is worked out, where a penalty can hide inside it, and then puts one household through all three paths with the arithmetic shown.
What a blend and extend is
A blend and extend is an arrangement with your current lender. Instead of breaking the mortgage, you start a new term today, and the time left on your old term is folded into it. The lender replaces your rate with a single blended rate that sits somewhere between the old one and today's.
"Blend" is the rate. "Extend" is the term: you usually come out with a fresh five-year term, so you're committed to the lender for longer than you were.
The appeal is that many lenders waive the separate penalty on a blend, because you're staying with them. The trade-off is that only part of your rate falls. You keep paying something close to your old rate for the months you had left, just averaged across a longer stretch.
How the blended rate is worked out
The usual starting point is a weighted average. Your current rate is weighted by the months left in your term, today's rate by the months being added, and the total is divided by the length of the new term.
Say you have 24 months left at 5.40%, and today's rate for a new five-year term is 3.90%. A five-year term is 60 months, so 36 months are being added:
(5.40 × 24 + 3.90 × 36) ÷ 60 = 4.50%
That's the blended rate before anything else is added. It's lower than what you pay now, higher than what a new borrower would get, and it runs for five years instead of two.
When a penalty is built into the rate
Not every lender quotes the weighted average. Some use their posted rates in the formula instead of the discounted rate you'd actually be offered. Some add a margin. Either way, part of what would have been a penalty ends up inside the rate, spread over the new term, where it's harder to see.
The way to find it is to compare. If your lender quotes 4.75% and the weighted average is 4.50%, the extra quarter point is the part worth asking about. On a $450,000 mortgage over five years, that quarter point adds an estimated $5,300 of interest. It doesn't mean the offer isn't worth taking, but it's worth knowing what's in it.
Blend, break or wait: one household
Nadia and Owen have a $450,000 balance with a big bank, at 5.40%, with 24 months left in a five-year term. There are 20 years left on the amortization. Their payment is an estimated $3,055 a month. A new five-year term is 3.90% today.
To compare fairly, each path runs over the same five years, from today to the end of a new term.
Break. Their bank measures the interest rate differential against its posted rate for a two-year term, about 5.77% in September 2026, less the 1.44-point discount they received in 2023. The comparison rate is 4.33%, and the estimated penalty is about $9,600, well above three months' interest of about $6,000. (How that works is in How is a mortgage penalty calculated in Canada?.) Their new payment at 3.90% is about $2,696.
Blend. No penalty, a rate of 4.50%, and a payment of about $2,837.
Wait. Carry on at $3,055 for two years, then renew. Nobody knows the rate in two years, so the scenario has to assume one. If it were 3.90%, the same as today, the payment would drop to about $2,724.
Here's what each path costs over the five years, as interest plus any penalty:
| Payment now | Penalty | Estimated five-year cost | |
|---|---|---|---|
| Break, penalty paid in cash | $2,696 | $9,630 | $89,100 |
| Blend at 4.50% | $2,837 | none | $92,100 |
| Wait, renew at 3.90% | $3,055 | none | $93,000 |
On these numbers, breaking comes out about $3,000 cheaper than blending, but it needs $9,600 in cash on the day. Added to the mortgage instead, the break path costs about $90,800, still around $1,300 less than the blend, with a payment of about $2,754. That margin could disappear in discharge and legal fees, which aren't included here.
The rate nobody knows
The wait path depends entirely on the renewal rate in two years, so it's worth running more than one.
| If rates in two years are | Wait costs about | Compared with the blend |
|---|---|---|
| 3.50% | $88,200 | $3,900 less |
| 3.90% | $93,000 | $900 more |
| 4.50% | $100,200 | $8,200 more |
| 5.00% | $106,300 | $14,200 more |
The point where waiting and blending cost the same is a renewal rate of about 3.82%. Below that, waiting comes out ahead. Above it, the blend does. That single number is often the clearest way to think about the choice: a blend is, in effect, a way of settling today what the next two years of rates are worth to you.
It may seem odd that waiting costs more even when renewal rates match today's. It's timing. The blend lowers the rate right away, while the balance is at its highest, and the interest saved early outweighs the higher rate later.
What changes the picture
The lender type. Nadia and Owen's bank uses posted rates less their discount. At a lender that compares with the rates it offers today, their penalty would be about $13,500, and the blend would be the cheapest of the three paths at these rates, by about $900 over breaking.
The quoted rate. If their bank quoted 4.75% instead of the weighted 4.50%, the blend's five-year cost would rise to about $97,300, the highest of the three. Waiting would then match it at a renewal rate of about 4.26%.
The extra commitment. A blend adds three years with the same lender. If you think you may move, need to refinance, or want to shop at renewal, that's part of the cost too.
Seeing your own numbers
The blend and extend calculator runs all three paths over the same window with your balance, rate and months left. It works out the weighted blend, lets you enter a rate your lender has quoted, and shows how far that quote sits from the weighted average. It also finds the renewal rate at which waiting and blending cost the same. It runs in your browser, and nothing you type is sent to us.
If breaking outright is the path you're weighing more closely, the break calculator goes into the penalty in more detail. And if you've been quoted a blended rate and would like a second opinion on it, a licensed broker can compare it with what other lenders would offer. You can book a free conversation if that would help.
Nadia and Owen are an illustrative composite. The penalty uses the Bank of Canada's typical big-bank posted rates as published in September 2026. All figures are estimates, with monthly payments and the semi-annual compounding Canadian fixed-rate mortgages use, and they exclude discharge, legal and appraisal fees. Your lender's figures will differ, and nothing here is a recommendation.