GDS/TDS Ratios Explained

Darrell McCollom • June 12, 2024

One of the major qualifiers lenders look at when considering your application for mortgage financing is your debt service ratios.


Now, before we get started, if you prefer to have someone walk through these calculations with you, assess your financial situation, and let you know exactly where you stand, let’s connect. There is no use in dusting off the calculator and running the numbers yourself when we can do it for you!


However, if you’re someone who likes to know the nitty-gritty of how things work instead of simply accepting that's just the way it is, this article is for you. But be warned, there are a lot of mortgage words and some math ahead; with that out of the way, let’s get started!

 

“Debt servicing” is the measure of your ability to meet all of your financial obligations. There are two ratios that lenders examine to determine whether you can debt service a mortgage.


The first is called the “gross debt service” ratio, or GDS, which is the percentage of your monthly household income that covers your housing costs. The second is called the “total debt service” ratio, or TDS, which is the percentage of your monthly household income covering your housing costs and all your other debts.


GDS is your income compared to the cost of financing the mortgage, including your proposed mortgage payments (principal and interest), property taxes, and heat (PITH), plus a percentage of your condo fees (if applicable).


Here’s how to calculate your GDS.


Principal + Interest + Taxes + Heat / Gross Annual Income


Your TDS is your income compared to your GDS plus the payments made to service any existing debts. Debts include car loans, line of credit, credit card payments, support payments, student loans, and anywhere else you’re contractually obligated to make payments.


Here’s how to calculate your TDS.


Principal + Interest + Taxes + Heat + Other Debts / Gross Annual Income


With the calculations for those ratios in place, the next step is to understand that each lender has guidelines that outline a maximum GDS/TDS. Exceeding these guidelines will result in your mortgage application being declined, so the lower your GDS/TDS, the better.


If you don’t have any outstanding debts, your GDS and TDS will be the same number. This is a good thing!


The maximum ratios vary for conventional mortgage financing based on the lender and mortgage product being offered. However, if your mortgage is high ratio and mortgage default insurance is required, the maximum GDS is 39% with a maximum TDS of 44%.


So how does this play out in real life? Well, let’s say you’re currently looking to purchase a property with a payment of $1700/mth (PITH), and your total annual household income is $90,000 ($7500/mth). The calculations would be $1700 divided by $7500, which equals 0.227, giving you a gross debt service ratio of 22.7%.


A point of clarity here. When calculating the principal and interest portion of the payment, the Government of Canada has instituted a stress test. It requires you to qualify using the government's qualifying rate (which is higher), not the actual contract rate. This is true for both fixed and variable rate mortgages.


Now let’s continue with the scenario. Let’s say that in addition to the payments required to service the property, you have a car payment of $300/mth, child support payments of $500/mth, and between your credit cards and line of credit, you’re responsible for another $700/mth. In total, you pay $1500/mth. So when you add in the $1700/mth PITH, you arrive at a total of $3200/mth for all of your financial obligations. $3200 divided by $7500 equals 0.427, giving you a total debt service ratio of 42.7%.


Here’s where it gets interesting. Based on your GDS alone, you can easily afford the property. But when you factor in all your other expenses, the TDS exceeds the allowable limit of 42% (for an insured mortgage anyway). So why does this matter? Well, as it stands, you wouldn’t qualify for the mortgage, even though you are likely paying more than $1700/mth in rent.


So then, to qualify, it might be as simple as shuffling some of your debt to lower payments. Or maybe you have 10% of the purchase price saved for a downpayment, changing the mortgage structure to 5% down and using the additional 5% to pay out a portion of your debt might be the difference you need to bring it all together.


Here’s the thing, as your actual financial situation is most likely different than the one above, working with an independent mortgage professional is the best way to give yourself options. Don’t do this alone. Your best plan is to seek and rely on the advice provided by an experienced independent mortgage professional. While you might secure a handful of mortgages over your lifetime, we do this every day with people just like you.


It’s never too early to start the conversation about mortgage qualification. Going over your application and assessing your debt service ratios in detail beforehand gives you the time needed to make the financial moves necessary to put yourself in the best financial position.


So if you find yourself questioning what you can afford or if you want to discuss your GDS/TDS ratios to understand the mortgage process a little better, please get in touch. It would be a pleasure to work with you, we can get a preapproval started right away.

Darrell McCollum

Employment and Mortgage Qualification: What Lenders Look For

By Darrell McCollom • April 1, 2026
When you apply for a mortgage, your employment history and status carry a lot of weight. Even if you feel secure in your job, lenders need proof that your income is reliable and will continue. To them, your employment status is one of the strongest indicators of whether you can make your mortgage payments long term. Here’s how lenders typically view different employment situations: Permanent Employment This is the gold standard. Once you’ve passed any probationary period and hold permanent status, lenders see you as a lower risk. It shows that your employer is committed to you, and your income is steady. Probationary Periods If you’re still on probation—usually 3 to 6 months, though sometimes longer—lenders may hesitate. That’s because your employer can end your contract without cause during this period. Once probation is over, you’re considered more secure. That said, context matters. If you’ve worked with the same company for years as a contractor and just transitioned into full-time employment, lenders may accept a letter from your employer confirming that probation is waived. Documentation is key here. Parental Leave Being on or about to take parental leave doesn’t mean you can’t qualify for a mortgage. As long as you have a letter from your employer guaranteeing your position and return-to-work date, lenders can use your regular salary—not your leave income—when assessing your application. Term Contracts This is one of the trickiest categories. Even highly skilled professionals with strong incomes can face challenges here. A term contract has a start and end date, which makes lenders question the stability of your future income. To use term-contract income, lenders generally want to see at least two years of history, or proof that your contract has already been renewed. The more evidence you can show of consistent employment, the stronger your case will be. The Bottom Line If you’re planning to apply for a mortgage, it’s important to understand how your employment status could affect your approval. Whether you’re starting a new job, coming back from leave, or working under contract, lenders want documentation that proves your income is reliable. 📞 If you’ve recently changed jobs or are planning a career shift, let’s connect. I can help you prepare your file so you qualify with confidence and avoid surprises in the approval process.

Your Guide to Real Estate Investment in Canada

By Darrell McCollom • March 25, 2026
Your Guide to Real Estate Investment in Canada Real estate has long been one of the most popular ways Canadians build wealth. Whether you’re purchasing your first rental property or expanding an existing portfolio, understanding how real estate investment works in Canada—and how it’s financed—is key to making smart decisions. This guide walks through the fundamentals you need to know before getting started. Why Canadians Invest in Real Estate Real estate offers several potential benefits as an investment: Long-term appreciation of property value Rental income that can support cash flow Leverage , allowing you to invest using borrowed funds Tangible asset with intrinsic value Portfolio diversification beyond stocks and bonds When structured properly, real estate can support both income and long-term net worth growth. Types of Real Estate Investments Investors typically focus on one or more of the following: Long-term residential rentals Short-term or vacation rentals (subject to local regulations) Multi-unit residential properties Pre-construction or assignment purchases Value-add properties that require renovations Each type comes with different financing rules, risks, and return profiles. Down Payment Requirements for Investment Properties In Canada, investment properties generally require higher down payments than owner-occupied homes. Typical minimums include: 20% down payment for most rental properties Higher down payments may be required depending on: Number of units Property type Borrower profile Lender guidelines Down payment source, income stability, and credit history all play a role in approval. How Rental Income Is Used to Qualify Lenders don’t always count 100% of rental income. Depending on the lender and mortgage product, they may: Use a rental income offset , or Include a percentage of rental income toward qualification Understanding how income is treated can significantly impact borrowing power. Financing Options for Investors Investment financing can include: Conventional mortgages Insured or insurable options (in limited scenarios) Alternative or broker-only lenders Refinancing equity from existing properties Purchase plus improvements for value-add projects Access to multiple lenders is often crucial for investors as portfolios grow. Key Costs Investors Should Plan For Beyond the purchase price, investors should budget for: Property taxes Insurance Maintenance and repairs Vacancy periods Property management fees (if applicable) Legal and closing costs A realistic cash-flow analysis is essential before buying. Risk Considerations Like any investment, real estate carries risk. Key factors to consider include: Interest rate changes Market fluctuations Tenant turnover Regulatory changes Liquidity (real estate is not easily sold quickly) A strong financing structure can help manage many of these risks. The Role of a Mortgage Professional Investment mortgages are rarely “one-size-fits-all.” Lender policies vary widely, especially as you acquire more properties. Working with an independent mortgage professional allows you to: Compare multiple lender strategies Structure financing for long-term growth Preserve flexibility as your portfolio evolves Avoid costly mistakes early on Final Thoughts Real estate investment in Canada can be a powerful wealth-building tool when approached with a clear strategy and proper financing. Whether you’re exploring your first rental property or planning your next acquisition, understanding the numbers—and the lending landscape—matters. If you’d like to discuss investment property financing, run the numbers, or explore your options, feel free to connect. A well-planned mortgage strategy can make all the difference in long-term success.