Last reviewed: June 2026
This page explains the assumptions behind the mortgage calculators on this website. It is intended to make the estimates easier to understand and independently check.
Payment estimate
The renewal calculator estimates a level mortgage payment from the remaining principal, the entered annual interest rate, the remaining amortization, and the selected payment frequency. Canadian fixed-rate mortgages commonly quote a nominal annual rate compounded semi-annually; an equivalent periodic rate is used for the selected payment schedule.
Renewal comparison
The current-rate and renewal-rate scenarios use the same entered balance and amortization so that the displayed payment difference isolates the rate change. A lump-sum amount is applied to principal before the renewal payment is estimated.
What the estimate excludes
- Lender-specific rounding and payment-date conventions.
- Mortgage insurance premiums, property taxes, and optional products.
- Discharge, appraisal, legal, transfer, or registration fees.
- Penalties, portability rules, and lender-specific prepayment limits.
- Variable-rate payment triggers or contract-specific adjustments.
How to use the result
Treat the result as a planning estimate, not a quote or recommendation. Confirm the rate, term, amortization, payment, fees, privileges, and calculation method in writing with your lender or mortgage professional before making a decision.
Questions about an estimate can be sent through our contact page.
Input Quality Matters
The estimate is only as useful as the information entered. Users should rely on a recent mortgage statement for the remaining balance and should confirm the remaining amortization with the lender before comparing offers.
Scenario Comparison
For a fair renewal comparison, change one input at a time. For example, compare the current rate with the proposed rate while keeping balance, amortization, and payment frequency the same. Then test prepayment or amortization changes separately.
Why This Is Not a Quote
A lender’s final payment may include contract-specific rounding, payment-date rules, insurance, fees, taxes, or optional products. The calculator can help estimate and organize questions, but it cannot replace the lender’s written calculation.
Tool methodology
Data Handling and Exported Reports
Copy, Print / PDF, Create Email Draft, and Save on This Device functions are designed to help users keep their own renewal planning notes. Calculations and summaries shown on the page remain educational estimates.
- Print / PDF controls use the browser print dialog. The site does not generate a server-side PDF file in this workflow.
- Local save uses browser storage on the device being used. It can be removed with Clear, Delete Saved Data, or by clearing browser data.
- Create Email Draft controls open a draft in the user’s own mail app when the browser supports it. This action should not subscribe users to marketing.
- Exported summaries include a generated date. They can become outdated if rates, lender fees, rules, or contract terms change.
Always confirm final numbers, fees, penalties, and contract terms with the written lender offer or a qualified professional.
Local privacy control
Manage Saved Data on This Device
Some tools can save your inputs in this browser’s local storage. You can remove those saved items here without contacting the server because these saves are not uploaded by the save function.
This action removes only Mortgage Renewal OS™ local saves from this browser. On a shared or public computer, use this before leaving the device.