Your income, debts, and expenses all play a major role in whether you qualify for a mortgage — and for how much. Our free Debt Service Calculator helps you figure out where you stand based on standard lender guidelines.
Lenders use two key ratios to assess your financial situation: Gross Debt Service (GDS) and Total Debt Service (TDS). These help determine how much of your income is going toward housing costs and total debt.
What This Calculator Measures
- GDS (Gross Debt Service Ratio) – the percentage of your income used for housing expenses like mortgage payments, property taxes, and utilities.
- TDS (Total Debt Service Ratio) – the percentage of income used for all monthly debts, including housing, credit cards, car payments, and loans.
By entering your income and monthly expenses, our calculator shows whether you meet the typical lending guidelines used by banks and mortgage brokers in Canada.
Why GDS and TDS Matter
When you apply for a mortgage, lenders want to be sure you can handle the payments — even if rates rise. The lower your debt ratios, the stronger your application.
Most lenders in Canada follow these standard limits:
- GDS ratio: Should be below 35%
- TDS ratio: Should be below 42%
Depending on your credit score, down payment, and lender policies, some exceptions may apply — especially if you’re working with an experienced mortgage broker in Toronto.
What You’ll Need to Use the Calculator
- Your gross (before-tax) monthly income
- Estimated mortgage payment (use our purchase calculator if needed)
- Monthly property tax and heating costs
- Monthly debt payments (credit cards, car loans, lines of credit, etc.)
How to Use the Results
- If your ratios are within guidelines, you’re likely in a good position to get approved.
- If your ratios are too high, we can help you strategize — whether that means lowering your debt, increasing your income, or adjusting your mortgage budget.
Ideal for Pre-Approval & Planning
Our Debt Service Calculator is the perfect tool to use before getting a mortgage pre-approval. It gives you a realistic snapshot of your financial health and helps answer:
- Will I qualify for the mortgage amount I want?
- Am I carrying too much debt to get approved?
- Can I afford a property in today’s market?
It’s especially helpful if you’re navigating the Toronto housing market, or comparing rates across lenders like BMO, and TD.
Need Help Improving Your Ratios?
If your GDS or TDS is just outside the qualifying range, don’t worry — we’ve helped hundreds of clients in similar situations. Our brokers can recommend:
- Debt consolidation into a lower-rate mortgage
- Refinancing options to reduce your monthly payments
- Alternative lenders with more flexible guidelines
Use the calculator above to run your numbers — then connect with a Mortgages.ca advisor to explore your options and create a plan that works for you.
Get clarity. Get qualified. Let’s make it happen.