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
By Darrell McCollom July 30, 2025
Bank of Canada holds policy rate at 2¾%. FOR IMMEDIATE RELEASE Media Relations Ottawa, Ontario July 30, 2025 The Bank of Canada today maintained its target for the overnight rate at 2.75%, with the Bank Rate at 3% and the deposit rate at 2.70%. While some elements of US trade policy have started to become more concrete in recent weeks, trade negotiations are fluid, threats of new sectoral tariffs continue, and US trade actions remain unpredictable. Against this backdrop, the July Monetary Policy Report (MPR) does not present conventional base case projections for GDP growth and inflation in Canada and globally. Instead, it presents a current tariff scenario based on tariffs in place or agreed as of July 27, and two alternative scenarios—one with an escalation and another with a de-escalation of tariffs. While US tariffs have created volatility in global trade, the global economy has been reasonably resilient. In the United States, the pace of growth moderated in the first half of 2025, but the labour market has remained solid. US CPI inflation ticked up in June with some evidence that tariffs are starting to be passed on to consumer prices. The euro area economy grew modestly in the first half of the year. In China, the decline in exports to the United States has been largely offset by an increase in exports to the rest of the world. Global oil prices are close to their levels in April despite some volatility. Global equity markets have risen, and corporate credit spreads have narrowed. Longer-term government bond yields have moved up. Canada’s exchange rate has appreciated against a broadly weaker US dollar. The current tariff scenario has global growth slowing modestly to around 2½% by the end of 2025 before returning to around 3% over 2026 and 2027. In Canada, US tariffs are disrupting trade but overall, the economy is showing some resilience so far. After robust growth in the first quarter of 2025 due to a pull-forward in exports to get ahead of tariffs, GDP likely declined by about 1.5% in the second quarter. This contraction is mostly due to a sharp reversal in exports following the pull-forward, as well as lower US demand for Canadian goods due to tariffs. Growth in business and household spending is being restrained by uncertainty. Labour market conditions have weakened in sectors affected by trade, but employment has held up in other parts of the economy. The unemployment rate has moved up gradually since the beginning of the year to 6.9% in June and wage growth has continued to ease. A number of economic indicators suggest excess supply in the economy has increased since January. In the current tariff scenario, after contracting in the second quarter, GDP growth picks up to about 1% in the second half of this year as exports stabilize and household spending increases gradually. In this scenario, economic slack persists in 2026 and diminishes as growth picks up to close to 2% in 2027. In the de-escalation scenario, economic growth rebounds faster, while in the escalation scenario, the economy contracts through the rest of this year. CPI inflation was 1.9% in June, up slightly from the previous month. Excluding taxes, inflation rose to 2.5% in June, up from around 2% in the second half of last year. This largely reflects an increase in non-energy goods prices. High shelter price inflation remains the main contributor to overall inflation, but it continues to ease. Based on a range of indicators, underlying inflation is assessed to be around 2½%. In the current tariff scenario, total inflation stays close to 2% over the scenario horizon as the upward and downward pressures on inflation roughly offset. There are risks around this inflation scenario. As the alternative scenarios illustrate, lower tariffs would reduce the direct upward pressure on inflation and higher tariffs would increase it. In addition, many businesses are reporting costs related to sourcing new suppliers and developing new markets. These costs could add upward pressure to consumer prices. With still high uncertainty, the Canadian economy showing some resilience, and ongoing pressures on underlying inflation, Governing Council decided to hold the policy interest rate unchanged. We will continue to assess the timing and strength of both the downward pressures on inflation from a weaker economy and the upward pressures on inflation from higher costs related to tariffs and the reconfiguration of trade. If a weakening economy puts further downward pressure on inflation and the upward price pressures from the trade disruptions are contained, there may be a need for a reduction in the policy interest rate. Governing Council is proceeding carefully, with particular attention to the risks and uncertainties facing the Canadian economy. These include: the extent to which higher US tariffs reduce demand for Canadian exports; how much this spills over into business investment, employment and household spending; how much and how quickly cost increases from tariffs and trade disruptions are passed on to consumer prices; and how inflation expectations evolve. We are focused on ensuring that Canadians continue to have confidence in price stability through this period of global upheaval. We will support economic growth while ensuring inflation remains well controlled. Information note The next scheduled date for announcing the overnight rate target is September 17, 2025. Read the July 30th., 2025 Monetary Report
By Darrell McCollom July 23, 2025
If you’re looking to purchase a property, although you might not think it matters too much, the source of your downpayment means a great deal to the lender. Let’s discuss the lender requirements, what your downpayment tells the lender about your financial situation, a how downpayment helps establish the mortgage loan to value. Anti-money laundering Lenders care about your downpayment source because, legally, they have to. To prevent money laundering, lenders have to document the source of the downpayment on every home purchase. Acceptable forms of downpayment are money from your resources, borrowed funds through an insured program called the FlexDown, or money you receive as a gift from an immediate family member. To prove the funds are from your resources and not laundered money from the proceeds of crime, you’ll be required to provide bank statements showing the money has been in your account for at least 90 days or that you’ve accumulated the funds through payroll deposits or other acceptable means. Now, if you’re borrowing all or part of your downpayment, you’ll need to include the costs of carrying the payments on the borrowed downpayment in your debt service ratios. If you’re the recipient of a gift from a direct family member, you’ll need to provide a signed gift letter indicating that the funds are a true gift and have no schedule for repayment. From there, you’ll need to show the money deposit into your account. Financial suitability Lenders care about the source of the downpayment because it is an indicator that you are financially able to purchase the property. Showing the lender that your downpayment is coming from your resources is the best. This demonstrates that you have positive cash flow and that you’re able to save money and manage your finances in a way that indicates you’ll most likely make your mortgage payments on time. If your downpayment is borrowed or from a gift, there’s a chance that they’ll want to scrutinize the rest of your application more closely. The bigger your downpayment, the better, well, as far as the lender is concerned. The way they see it, there is a direct correlation between how much money you have as equity to the likelihood you will or won’t default on their mortgage. Essentially, the more equity you have, the less likely you will walk away from the mortgage, which lessens their risk. Downpayment establishes the loan to value (LTV) Thirdly, your downpayment establishes the loan to value ratio. The loan to value ratio or LTV is the percentage of the property’s value compared to the mortgage amount. In Canada, a lender cannot lend more than 95% of a property’s value. So, if you’re buying a home for $400k, the lender can lend $380k, and you’re responsible for coming up with 5%, $ 20k in this situation. But you might be asking yourself, how does the source of the downpayment impact LTV? Great question, and to answer this, we have to look at how to establish property value. Simply put, something is worth what someone is willing to pay for it and what someone is willing to sell it for. Of course, within reason, having no external factors coming into play. When dealing with real estate, an appraisal of the property will include comparisons of what other people have agreed to pay for similar properties in the past. You’ll often hear of situations where buyers and sellers try to inflate the sale price to help finalize the transaction artificially. Any scenario where the buyer isn’t coming up with all of the money for the downpayment, independent of the seller, impacts the LTV. All details of a real estate transaction purchase and sale have to be disclosed to the lender. If there’s any money transferring behind the scenes, this impacts the LTV, and the lender won’t proceed with financing. Non-disclosure to the lender is mortgage fraud. So there you have it; hopefully, this provides context to why lenders ask for documents to prove the source of your downpayment. If you’d like to talk about mortgage financing, please connect anytime; it would be a pleasure to work with you.