Updated: April 2025  |  bremo.io financial guides

Debt-to-Income Ratio in Canada: What Lenders Look At

When you apply for a mortgage, car loan, or any significant line of credit in Canada, lenders assess how much of your income is already committed to debt payments. The primary measures are the Gross Debt Service (GDS) ratio and the Total Debt Service (TDS) ratio.

Understanding how these ratios work — and how to improve them — can mean the difference between approval and rejection, or between a competitive rate and a high-risk premium.

Gross Debt Service (GDS) Ratio

The GDS ratio measures the percentage of your gross monthly income consumed by housing costs:

GDS = (Mortgage Principal + Interest + Property Taxes + Heat) / Gross Monthly Income

If applicable, 50% of condo fees are also included. Lenders in Canada generally want your GDS ratio to be 39% or lower. CMHC (Canada Mortgage and Housing Corporation) insured mortgages require a maximum GDS of 39%.

Total Debt Service (TDS) Ratio

The TDS ratio adds all other debt payments to the housing costs in the GDS calculation:

TDS = (Housing Costs + Car Loan + Credit Cards + All Other Debt Payments) / Gross Monthly Income

The standard maximum TDS ratio for CMHC-insured mortgages is 44%. Conventional (non-insured) lenders may be slightly more flexible, but most want to see TDS under 43–44%.

How Credit Cards Are Counted

For TDS purposes, lenders use a minimum payment estimate on credit card balances — typically 3% of the outstanding balance per month. If you carry a $100 credit card balance, lenders calculate $300/month as a debt obligation, even if you pay more.

This is why carrying high credit card balances can significantly hurt your mortgage qualification, even if you are managing the payments.

Calculating Your TDS Ratio

1. Add up all monthly housing costs (mortgage, property tax, heat, condo fees ÷ 2)
2. Add monthly payments on car loans, personal loans, student loans, lines of credit
3. Add 3% of all credit card balances
4. Divide total by your gross monthly income (before tax)
5. Multiply by 100 for the percentage

Debt-to-Income for Personal Finance (Not Mortgages)

Beyond lender qualification, your personal debt-to-income ratio — measured against your net (after-tax) income — is a useful health indicator:

• Under 15%: Consumer debt payments are comfortable
• 15–20%: Manageable but worth monitoring
• 20–30%: High — limited flexibility, little savings capacity
• 30%+: Debt stress territory — reducing debt should be a priority

Improving Your Debt-to-Income Ratio

You can improve your TDS ratio by either increasing income or reducing debt:

• Pay down credit card balances (reduces the 3% monthly obligation calculation)
• Pay off or sell a high-payment vehicle
• Consolidate multiple loans into a single lower payment
• Increase income through a raise, additional work, or rental income
• Avoid taking on new debt before a major application

Stress Test and High DTI

Canada's mortgage stress test requires qualification at the higher of the contract rate + 2% or the benchmark rate set by OSFI. This means even borrowers with a manageable TDS at their actual rate must show they could still afford payments at a higher rate. High existing debt loads make passing the stress test harder.

When High DTI Signals a Bigger Problem

If your TDS ratio is high not because of housing but because of consumer debt, this suggests a structural debt problem that credit products may not solve. In that case, a free consultation with a Licensed Insolvency Trustee may help you understand options like a consumer proposal that would significantly reduce your monthly obligations.