Is this a good rate?Second opinion · Canada

Mortgage rates4 min readUpdated October 30, 2026

Blend and extend: how a blended mortgage rate is worked out

When rates have fallen since you signed, a closed mortgage can feel like a trap: breaking it means a penalty, and waiting means paying the old rate for the rest of the term. Some lenders offer a middle path called a blend and extend. Instead of breaking the contract, you extend it into a new, longer term, and the lender combines your existing rate with its current rate into a single blended rate. Here is how that works for one illustrative household, and the questions that decide whether it is a good deal.

Key points

  • A blend and extend combines your current rate with a new rate over a longer term, instead of breaking the mortgage.
  • A simple estimate weights each rate by the months it covers; lenders use their own methods, so ask for the blended rate in writing.
  • Compare the blended rate with two alternatives: breaking and re-signing at today's rate, and waiting until renewal.
  • Grade the blended rate like any other offer, because it will be your rate for the whole new term.

The situation: two years left at a higher rate

Picture an illustrative household (call them the Okafors) three years into a five-year fixed mortgage at 5.49%. They owe about $400,000 and have 24 months left. In this example the lender's current five-year rate is 4.29%, and the gap is starting to sting.

They have three options. They can wait and renew in two years without a prepayment penalty. They can break the mortgage now, pay the penalty and sign a new one. Or they can ask the lender for a blend and extend. Each one costs something, so the job is to put a number on each.

Option one: break the mortgage

Breaking a closed mortgage usually costs the higher of three months' interest or an interest rate differential. With a balance of $400,000, a contract rate of 5.49%, 24 months left and a comparison rate of 4.29%, three months' interest is $5,490 and the simplified IRD is $9,600. The penalty would be $9,600, from the interest rate differential.

The lender's real comparison rate could be different, and many lenders use posted rates in the calculation, which can make the figure larger. Our guide to prepayment penalties explains why, and the prepayment penalty estimator lets you try other inputs.

Worked exampleThe penalty for breaking instead
Balance
$400,000
Contract rate
5.49%
Comparison rate
4.29%
Months left
24
Three months' interest
$5,490
Simplified IRD
$9,600
Likely penalty (larger)
$9,600
Method
the interest rate differential
Assumptions: Illustrative: $400,000 balance, 5.49% contract rate, 24 months left, and a 4.29% comparison rate; simplified interest rate differential. Computed by the site's calculators.

Option two: blend and extend

Instead of breaking, the Okafors extend into a new 60-month term starting today. A simple way to estimate the result is to weight each rate by the months it covers: the old rate of 5.49% for the 24 months they had already agreed to, and the new rate of 4.29% for the rest of the new term. That gives a blended rate of about 4.77% for the full 60 months.

In effect, the old rate keeps applying for the months already agreed, but it is averaged into a single rate for the whole new term. Whether any separate penalty or fee applies, and how the lender sets the new-rate portion, are questions for the lender.

Worked exampleAn illustrative blend
Current rate
5.49%
New rate
4.29%
Blended rate
4.77%
Months left
24
New term (months)
60
Assumptions: Illustrative: an existing rate of 5.49% with 24 months left, extended into a new 60-month term with 4.29% applied to the extra months; a simple time-weighted blend. Computed by the site's calculators.
Mitey the yeti holds a clipboard and points down and to the left
Unblend it: set the blended rate beside what breaking would cost.

How the Okafors judged the blended rate

A blended rate is still a rate for a new five-year term, so they scored it like any other offer. At 4.77%, the fixed mortgage checker gives 69 out of 100 ("grade C"), 0.43% above a best published rate of 4.34%, worth about $8,241 over the 5-year term.

Then they compared it with option one: paying the $9,600 penalty and signing a new five-year mortgage at 4.29%. The renewal switch calculator can show how long the lower rate takes to pay back a cost of that size. Finally, they compared both with simply waiting two years for renewal, when no prepayment penalty applies.

Worked exampleGrading the blended rate
Rate
4.77%
Score
69
Verdict
grade C
grade
C
Benchmark
4.34%
typical
4.83%
Gap
0.43%
Direction
above
Cost vs benchmark
$8,241
Assumptions: A $400,000 uninsured five-year fixed mortgage with a 25-year amortization at 4.77% (the illustrative blended rate), graded against the lowest published rate in Ontario at this page's last update. Computed by the site's calculators.

When the blend works the other way

Blending is not only for falling rates. If your current rate is lower than today's, a blend pulls your rate up. With an illustrative old rate of 3.29%, 24 months left and a new rate of 4.59%, the simple blend over 60 months comes to 4.07%.

A household might still choose that to lock in a rate for longer, or because it needs to change the mortgage for another reason. The trade-off is giving up the remaining months at the lower rate earlier than necessary. If rates are higher than your current rate, our guide to renewing when rates are higher covers the alternatives.

What to ask before you sign

With those answers you can line up all three options in dollars. The renewal checklist is useful if you decide to wait, and the renewal script has wording for asking your lender to improve its offer.

  1. What is the blended rate, and how did you calculate it? Please put it in writing.
  2. What rate did you use for the new portion: a posted rate or a discounted one?
  3. Are there any fees or a separate penalty?
  4. When does the new term end, and what are the prepayment privileges and penalty terms for it?
  5. What would my penalty be if I broke the mortgage instead, for the same date?

Questions people ask

Does every lender offer blend and extend?

It depends on the lender and on your mortgage. Ask your lender whether it offers one, and how it calculates the blended rate.

Does a blend and extend avoid the prepayment penalty?

It avoids breaking the contract, but ask the lender directly whether any penalty or fee applies and whether the cost of leaving your old rate early is built into the blended rate.

How accurate is the blend-and-extend calculator?

It gives a simple time-weighted estimate. Lenders use their own methods, so treat it as a check on the lender's written figure rather than a substitute for it.

Is a blend and extend better than waiting for renewal?

It depends on the numbers. Waiting means paying the old rate until the term ends, but with no prepayment penalty. A blend gives a lower rate sooner, but locks in a new term at a blended rate. Compare the interest cost of each over the same period.

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