GDS/TDS Ratios Explained

Dan Caird • January 10, 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.


Share

DAN CAIRD
Mortgage Agent | DLC

RECENT POSTS

Bank of Canada Rate Announcement Jan 28th, 2026

By Dan Caird • January 28, 2026
Bank of Canada maintains policy rate at 2¼%. FOR IMMEDIATE RELEASE Media Relations Ottawa, Ontario January 28, 2026 The Bank of Canada today held its target for the overnight rate at 2.25%, with the Bank Rate at 2.5% and the deposit rate at 2.20%. The outlook for the global and Canadian economies is little changed relative to the projection in the October Monetary Policy Report (MPR). However, the outlook is vulnerable to unpredictable US trade policies and geopolitical risks. Economic growth in the United States continues to outpace expectations and is projected to remain solid, driven by AI-related investment and consumer spending. Tariffs are pushing up US inflation, although their effect is expected to fade gradually later this year. In the euro area, growth has been supported by activity in service sectors and will get additional support from fiscal policy. China’s GDP growth is expected to slow gradually, as weakening domestic demand offsets strength in exports. Overall, the Bank expects global growth to average about 3% over the projection horizon. Global financial conditions have remained accommodative overall. Recent weakness in the US dollar has pushed the Canadian dollar above 72 cents, roughly where it had been since the October MPR. Oil prices have been fluctuating in response to geopolitical events and, going forward, are assumed to be slightly below the levels in the October report. US trade restrictions and uncertainty continue to disrupt growth in Canada. After a strong third quarter, GDP growth in the fourth quarter likely stalled. Exports continue to be buffeted by US tariffs, while domestic demand appears to be picking up. Employment has risen in recent months. Still, the unemployment rate remains elevated at 6.8% and relatively few businesses say they plan to hire more workers. Economic growth is projected to be modest in the near term as population growth slows and Canada adjusts to US protectionism. In the projection, consumer spending holds up and business investment strengthens gradually, with fiscal policy providing some support. The Bank projects growth of 1.1% in 2026 and 1.5% in 2027, broadly in line with the October projection. A key source of uncertainty is the upcoming review of the Canada-US-Mexico Agreement. CPI inflation picked up in December to 2.4%, boosted by base-year effects linked to last winter’s GST/HST holiday. Excluding the effect of changes in taxes, inflation has been slowing since September. The Bank’s preferred measures of core inflation have eased from 3% in October to around 2½% in December. Inflation was 2.1% in 2025 and the Bank expects inflation to stay close to the 2% target over the projection period, with trade-related cost pressures offset by excess supply. Monetary policy is focused on keeping inflation close to the 2% target while helping the economy through this period of structural adjustment. Governing Council judges the current policy rate remains appropriate, conditional on the economy evolving broadly in line with the outlook we published today. However, uncertainty is heightened and we are monitoring risks closely. If the outlook changes, we are prepared to respond. The Bank is committed to ensuring that Canadians continue to have confidence in price stability through this period of global upheaval. Information note The next scheduled date for announcing the overnight rate target is March 18, 2026. The Bank’s next MPR will be released on April 29, 2026. Read the January 28th, 2026 Monetary Report

What Is a Cashback Mortgage and How Does It Work?

By Dan Caird • January 21, 2026
Cashback Mortgages: Are They Worth It? Here’s What You Need to Know If you’ve been exploring mortgage options and come across the term cashback mortgage , you might be wondering what exactly it means—and whether it’s a smart move. Let’s break it down in simple terms. What Is a Cashback Mortgage? A cashback mortgage is just like a regular mortgage—but with one extra feature: you receive a lump sum of cash when the mortgage closes . This cash is typically: A fixed amount , or A percentage of the total mortgage , usually between 1% and 7% , depending on your mortgage term and lender. The money is tax-free and paid directly to you on closing day. What Can You Use the Cashback For? There are no restrictions on how you use the funds. Here are some common uses: Covering closing costs Buying new furniture Renovations or home upgrades Paying off high-interest debt Boosting your cashflow during a tight transition Whether it’s to help you settle in or catch up financially, cashback can offer a helpful buffer— but it comes at a cost . The True Cost of a Cashback Mortgage Here’s the part many people overlook: cashback mortgages come with higher interest rates than standard mortgages. Why? Because the lender is essentially advancing you a small loan upfront—and they’re going to make that money back (and then some) through your mortgage payments. So while the upfront cash feels like a bonus, you’ll pay more in interest over time to have that convenience. Breaking Down the Numbers It’s hard to give a blanket answer about how much more you’ll pay since it depends on: Your interest rate The cashback amount The mortgage term Your payment schedule This is why it’s important to run the numbers with a mortgage professional who can help you compare this option with others based on your personal financial situation. Are You Eligible for a Cashback Mortgage? Not everyone qualifies. Cashback mortgages generally come with stricter requirements . Lenders often want to see: Excellent credit history Strong, stable income Low debt-to-income ratio If your mortgage file includes anything “outside the box”—like being self-employed or recently changing jobs—qualifying for a cashback mortgage might be tough. What If You Need to Break the Mortgage? This is one of the biggest risks with cashback mortgages. If your circumstances change and you need to break your mortgage early, you could be on the hook for: Paying back some or all of the cashback you received, and A prepayment penalty (typically the interest rate differential or 3 months’ interest—whichever is higher) That can be a very expensive combination. So if there’s even a chance you might need to sell, refinance, or move before your term is up, a cashback mortgage might not be the best fit. Should You Consider a Cashback Mortgage? Maybe—but only with eyes wide open. Cashback mortgages can be helpful in the right scenario, but they’re not free money. They’re a lending tool that benefits the lender , and the key is knowing exactly what you’re agreeing to. Final Thoughts: Talk to an Expert First Choosing the right mortgage isn’t just about the lowest rate or the biggest perk—it’s about making a choice that fits your whole financial picture. If you’re considering a cashback mortgage, or just want to explore all your options, let’s talk. As an independent mortgage professional , I can help you weigh the pros and cons of various products, so you can make a confident, informed decision. Have questions? I’d be happy to help—reach out anytime.