What Are GDS/TDS Ratios Anyways?

Erik Sepper • March 5, 2025

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.


ERIK SEPPER 
MORTGAGE AGENT

CONTACT ME

Bank of Canada Holds Rate at 2.25% — April 29, 2026

By Erik Sepper • April 29, 2026
The Bank of Canada announced today that it is holding its target for the overnight rate at 2.25%, with the Bank Rate at 2.5% and the deposit rate at 2.20%. This decision comes against a backdrop of significant global uncertainty — and for Canadian homeowners, buyers, and anyone with a mortgage coming up for renewal, here's what it means.

Deposit vs. Down Payment: Key Differences for Homebuyers

By Erik Sepper • April 22, 2026
When you’re buying a home, two terms often cause confusion: deposit and down payment . While they’re related, they serve very different purposes in the homebuying process. Here’s what you need to know. What Is a Deposit? A deposit is the money you provide when you make an offer on a property. Think of it as a show of good faith that proves you’re serious about purchasing. How it works : Typically, you provide a certified cheque or bank draft that your real estate brokerage holds in trust. If your offer is accepted, the deposit remains in trust until the deal moves forward. If negotiations fall through, the deposit is refunded. Connection to your down payment : Once the sale is finalized, your deposit becomes part of your total down payment. Why it matters : The amount is negotiable, but a larger deposit can make your offer more attractive in a competitive market. Keep in mind, however, that if you back out after conditions are removed, you risk losing your deposit. What Is a Down Payment? Your down payment is the amount you contribute toward the purchase price of your home when securing a mortgage. Minimum requirement : In Canada, the minimum down payment is 5% of the home’s purchase price. Anything less than 20% requires mortgage default insurance. Sources : Down payments can come from your savings, the sale of another property, RRSP withdrawals (through the Home Buyers’ Plan), a gift from family, or even borrowed funds. Example: How They Work Together Imagine you’re buying a $400,000 home with a 10% down payment ($40,000). When you make your offer, you provide a $10,000 deposit . Once conditions are met, that deposit is transferred to your lawyer’s trust account. At closing, you add the remaining $30,000 to complete your full down payment. The lender provides the rest—$360,000—through your mortgage. The Bottom Line Your deposit shows commitment and secures your offer, while your down payment is what makes the mortgage possible. Together, they work hand in hand to get you into your new home. 📞 If you’d like clarity on deposits, down payments, or any other part of the mortgage process, let’s connect. I’d be happy to walk you through it step by step.

Employment and Mortgage Qualification: What Lenders Look For

By Erik Sepper • April 15, 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.