Gross Debt Service Ratio (GDS)
Understand the Gross Debt Service Ratio (GDS) in Canadian real estate, how it’s calculated, and why it’s essential for mortgage approval and affordability.
May 22, 2025
What is Gross Debt Service Ratio (GDS)?
The Gross Debt Service Ratio (GDS) is a financial metric used by lenders to determine how much of a borrower's income is required to cover housing-related costs.
Why Gross Debt Service Ratio (GDS) Matters in Real Estate
In Canadian real estate, the GDS ratio is one of the key factors used to assess mortgage affordability. It calculates the percentage of a borrower’s gross monthly income that goes toward housing expenses, including:
- Mortgage principal and interest
- Property taxes
- Heating costs
- 50% of condominium fees (if applicable)
The general guideline is that a borrower’s GDS should not exceed 32%. Staying within this threshold ensures that the buyer has sufficient income to manage their housing costs without financial strain.
A low GDS indicates a lower financial risk for lenders and increases the likelihood of mortgage approval. Conversely, a high GDS may signal overextension, prompting lenders to reduce the loan amount or request a larger down payment.
Buyers should calculate their GDS early in the homebuying process to understand what price range they can realistically afford and improve their financial position if necessary.
Example of Gross Debt Service Ratio (GDS)
A couple earns $8,000 per month. Their total monthly housing expenses are $2,400. Their GDS ratio is 30%, which falls within acceptable limits for most Canadian lenders.
Key Takeaways
- Measures how much of your income goes toward housing expenses.
- Lenders typically require a GDS of 32% or less.
- Includes mortgage, taxes, heating, and 50% of condo fees.
- Helps determine mortgage affordability and approval.
- Crucial for budgeting and long-term financial health.
Related Terms
- Total Debt Service Ratio (TDS)
- Mortgage Pre-Approval
- Affordability
- Debt-to-Income Ratio
- Mortgage Qualification
National average resale-price growth and housing-starts growth, smoothed over three months. The comparison illustrates the cycle; it does not establish how much a price change causes construction to change.
Trailing 12-month starts in centres of 50,000 or more remove the usual monthly seasonality. Ownership combines the homeowner and condominium categories; rental is shown separately.
Six-month averages of provincial starts, expressed at annual rates. The smoothing reduces the influence of individual apartment projects.
The same August benchmark compared with two different starting points. Three-month changes are not annualized.
Average sale prices show the difference in purchase costs across markets. They do not measure affordability relative to local incomes or construction costs.
Newfoundland and Labrador remains above its pre-pandemic sales pattern, but August activity was below last year. Historical lines retain their original release vintages.
Average and median describe different aspects of the same month’s transactions. Both are affected by the mix of homes sold.
Category averages compare different homes and locations; the gaps are not estimates of the cost to upgrade an otherwise identical property.
The five categories shown account for 5,000 of the board’s 5,057 sales. The remaining 57 transactions were in other housing categories.
Monthly observations are not seasonally adjusted. Active listings count properties available at month-end; they are not construction inventory.
Average and median prices share one dollar axis. These unadjusted transaction measures do not control for changes in the homes sold.
TRREB’s 416/905 categories compare the apartments sold in each area. The difference does not isolate a location premium for equivalent units.
5680 Oak Street in Vancouver and its surrounding context. (MCMP Architects)
Ground-level renderings of the tower proposed for 5680 Oak Street in Vancouver. (MCMP Architects)
