Mortgage Penalty Calculator

What this calculator does

It estimates what your lender would charge to let you out of your mortgage today, calculated both ways Canadian lenders actually do it — not just the method that produces the friendlier number.

Most lender websites show one figure with no explanation of how it was built. That makes it impossible to tell whether a quoted charge is ordinary or unusually large. This page shows three months’ interest, the standard differential that monolines and most credit unions use, and the posted-rate differential the big banks use, side by side, so the difference between them is visible rather than assumed.

• Three months’ interest, which is the floor on any fixed-rate charge
• The differential under both methods, and what the difference is worth
• Your charge in months of interest, so the number has some scale to it
• When waiting actually reduces the charge — and the month it stops helping
• What an unused prepayment privilege would take off, if your lender allows it

Why the bank’s number is so much larger

Both methods start the same way: take the gap between your contract rate and a comparison rate, multiply by your balance and by the months left in your term. The entire difference lies in which comparison rate gets used.

A monoline or credit union generally compares your rate against what they are charging today for a term about as long as you have left. A big bank instead takes today’s posted rate — the sticker price nobody actually pays — and subtracts the discount you negotiated when you signed. If you got 2% off posted back then, that 2% comes off today’s posted rate before the comparison is made, which pushes the comparison rate far below any real market rate and widens the gap against your contract rate.

This is the mechanism, and it is worth understanding precisely: the better you negotiated when you signed, the larger your penalty is now. It is written into the contract rather than being applied at anyone’s discretion, which is why arguing about fairness rarely gets anywhere and asking which method applies to your file usually does.

• Both methods multiply a rate gap by your balance and your months remaining
• The standard method compares against the lender’s current rate
• The posted-rate method compares against posted less your original discount
• A larger discount at signing means a larger charge today
• Which method applies is set by your contract, not by negotiation

Three months’ interest, and when it is the whole story

Three months’ interest is your balance times your contract rate, divided by four. On a variable-rate mortgage that is the entire charge at nearly every Canadian lender — a differential is not charged at all, which is one of the genuine advantages of a variable rate that rarely gets mentioned when rates are being compared.

On a fixed-rate mortgage it is the floor. You are charged the greater of three months’ interest and the differential, so you never pay less than the floor and frequently pay a good deal more.

This is why reading your charge in months of interest is useful. If it comes out at three months, the floor is binding and no differential is in play. If it comes out at six or ten months, a differential is driving it, and the size tells you roughly how far above current rates your contract sits.

• Three months’ interest = balance × contract rate ÷ 4
• On a variable rate, that is the whole charge
• On a fixed rate, it is the minimum — the differential can be far higher
• A charge of exactly three months means no differential applies
• Anything well above three months means your rate sits above today’s

When waiting helps, and when it stops

The differential scales directly with the months left in your term, so it shrinks every month that passes. That makes waiting a real lever — but only up to a point, and the point matters.

Because the charge is the greater of the differential and the three-month floor, the decline stops as soon as the differential falls below the floor. From there to renewal the charge is flat. On the default numbers the charge falls from $12,675 to the $5,951 floor by the time twelve months remain, and then does not move again. Waiting fourteen months saves $6,724; waiting the last twelve saves nothing at all.

That is a more useful thing to know than "the penalty disappears at renewal", which is true but tells you nothing about the year before it. The calculator computes the month your charge reaches its floor and shows the whole decline, so you can see whether delaying is worth anything in your particular case.

• The differential falls in proportion to the months remaining
• The charge stops falling once the differential drops below the floor
• After that month, waiting achieves nothing until renewal
• The page computes that month for your numbers rather than generalising
• At renewal itself there is no charge at all

Using your prepayment privilege first

Both formulas are proportional to the balance, so reducing the balance before the discharge reduces the charge in the same proportion. If your lender permits you to make your annual lump-sum prepayment immediately before paying the mortgage out, a 15% privilege takes roughly 15% off the charge.

This is a genuine saving rather than a shuffle, and it is worth being clear about why. A discharge repays the whole balance regardless — making part of that payment as a privilege first does not change how much principal you repay, only what the charge is calculated against. The difference is money you keep.

The catch is permission. Many lenders explicitly disallow a privilege payment made in contemplation of a discharge, and some will reverse it. This is a question to put in writing before you count on the saving, not one to assume from a calculator.

• Both the floor and the differential scale with the balance
• So a 15% privilege payment takes about 15% off the charge
• You repay the same principal either way — only the charge changes
• Many lenders do not permit this immediately before a discharge
• Get the answer in writing before treating the saving as real

Using your results well

Treat this as a sanity check on a payout statement, not a replacement for one. Only your lender can produce the binding figure, and the wording of your own contract governs. If their number is materially above this estimate, ask which method they applied and which comparison rate they used — lenders are required to disclose the methodology on request, and the answer is often where the discrepancy lives.

Then remember what this page does not tell you. It prices the charge; it does not tell you whether breaking is worth it. That depends on what a lower rate would save over your remaining term, which is a separate calculation and the one that should actually drive the decision.

And before assuming you have to pay it at all, check whether porting or blending applies. If you are buying another property inside your lender’s porting window the charge often disappears entirely, and a blend-and-extend can fold it into a new rate instead of demanding it in cash.

• Get an official payout statement before acting on any estimate
• Ask which method and which comparison rate were used
• Check whether a privilege payment is permitted before a discharge
• Price porting and blending before assuming the charge is unavoidable
• Take the figure to a break-versus-stay comparison before deciding