Separate rent from the property being financed from rent on other properties. Then match the inclusion percentage and method to the lender program.
Which property earns the rent?
The subject property is the property you are purchasing, refinancing or transferring. It may be a rental property or a home with a rental suite. In MyMortgageMate, enter that rent in the rental section on Properties & Results and enable Include this property's rental income.
Rent from a different property belongs in Properties Owned, alongside that property's mortgage payment and carrying costs. Selecting Rental Income on the Income page opens guidance; its amount box is disabled so the same rent is not counted again as ordinary income.
There is no universal rent percentage
CMHC describes different rental-income approaches depending on occupancy, unit count and whether the property is part of the mortgage application. That is why a single percentage cannot stand in for every program. CMHC's rental-income guidance sets out those distinctions.
The calculator's inclusion choices run from 0% to 100% in 5% steps. Those are modelling controls, not a list of percentages every lender accepts. Choose the percentage and method supported by the lender, insurer and documentation for the property.
One property, two different models
Consider an additional rental property that is wholly owned by the applicant. Monthly gross rent is $2,000, the selected inclusion is 50%, and monthly carrying costs in this example are $1,800.
The rent used by the model is $2,000 × 50% = $1,000 per month.
- Add-Back: in the calculator's additional-property model, $12,000 a year is added to income used for TDS, while the $1,800 monthly property carrying cost stays in the debt calculation.
- Offset: the included $1,000 rent is applied against the $1,800 carrying cost, leaving an $800 monthly shortfall for the debt calculation.
These approaches change different parts of the calculation. They are not interchangeable, and the model producing the better ratio is not automatically the lender's permitted method. Treatment of a surplus or a subject-property rental can also differ.
Check the inputs before comparing ratios
- Enter monthly gross rent, not an annual total or a rent figure already reduced by the inclusion percentage.
- Record property tax, heat, condo fees where applicable, and the correct mortgage payment with the property they belong to.
- Check occupancy, the selected rental method and any ownership share used in the other-property model.
- Use rent and property information that can be supported for the application.
For example, entering $1,000 because you already halved $2,000 rent, then choosing 50% inclusion, counts only $500. Entering the same $2,000 again on a second property row has the opposite effect. Both mistakes change the ratios without changing the actual rent.
Make the comparison easy to review
Keep the property details constant while comparing one rate or amortization change at a time. Review the rental method and inclusion notes with the resulting GDS and TDS figures, then print the scenario summary for your file.
Rental treatment is a qualification assumption, not a guarantee that every dollar of rent is available to spend. Use the lender's required rental worksheet for the final application and reconcile any difference in income, costs or qualifying payment.
Put the figures into a scenario
Use the appropriate assumptions, compare the results and save a summary for your file.
Open the Residential Calculator →Sources and review
References checked September 22, 2026. Examples are illustrative; confirm the lender, insurer and program requirements for your situation.