GDS/TDS Ratios Explained

Amy Kinvig • June 26, 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.

Amy Kinvig

Divorce and Your Mortgage: What You Need to Know

By Amy Kinvig • November 19, 2025
Going Through a Separation? Here’s What You Need to Know About Your Mortgage Separation or divorce can be one of life’s most stressful transitions—and when real estate is involved, the financial side of things can get complicated fast. If you and your partner own a home together, figuring out what happens next with your mortgage is a critical step in moving forward. Here’s what you need to know: You’re Still Responsible for Mortgage Payments Even if your relationship changes, your obligation to your mortgage lender doesn’t. If your name is on the mortgage, you’re fully responsible for making sure payments continue. Missed payments can lead to penalties, damage your credit, or even put your home at risk of foreclosure. If you relied on your partner to handle payments during the relationship, now is the time to take a proactive role. Contact your lender directly to confirm everything is on track. Breaking or Changing Your Mortgage Comes With Costs Dividing your finances might mean refinancing, removing someone from the title, or selling the home. All of these options come with potential legal fees, appraisal costs, and mortgage penalties—especially if you’re mid-term with a fixed-rate mortgage. Before making any decisions, speak with your lender to get a clear picture of the potential costs. This info can be helpful when finalizing your separation agreement. Legal Status Affects Financing If you're applying for a new mortgage after a separation, lenders will want to see official documentation—like a signed separation agreement or divorce decree. These documents help the lender assess any ongoing financial obligations like child or spousal support, which may impact your ability to qualify. No paperwork yet? Expect delays and added scrutiny in the mortgage process until everything is finalized. Qualifying on One Income Can Be Tougher Many couples qualify for mortgages based on combined income. After a separation, your borrowing power may decrease if you're now applying solo. This can affect your ability to buy a new home or stay in the one you currently own. A mortgage professional can help you reassess your financial picture and identify options that make sense for your situation—whether that means buying on your own, co-signing with a family member, or exploring government programs. Buying Out Your Partner? You May Have Extra Flexibility In cases where one person wants to stay in the home, lenders may offer special flexibility. Unlike traditional refinancing, which typically caps borrowing at 80% of the home’s value, a “spousal buyout” may allow you to access up to 95%—making it easier to compensate your former partner and retain the home. This option is especially useful for families looking to minimize disruption for children or maintain community ties. You Don’t Have to Figure It Out Alone Separation is never simple—but with the right support, you can move forward with clarity and confidence. Whether you’re keeping the home, selling, or starting fresh, working with a mortgage professional can help you understand your options and create a strategy that aligns with your new goals. Let’s talk through your situation and explore the best path forward. I’m here to help.

First-Time Buyer? Here’s How to Tell If You’re Ready

By Amy Kinvig • November 12, 2025
Ready to Buy Your First Home? Here’s How to Know for Sure Buying your first home is exciting—but it’s also a major financial decision. So how can you tell if you’re truly ready to take that leap into homeownership? Whether you’re confident or still unsure, these four signs are solid indicators that you’re on the right path: 1. You’ve Got Your Down Payment and Closing Costs in Place To purchase a home in Canada, you’ll need at least 5% of the purchase price as a down payment. In addition, plan for around 1.5% to 2% of the home’s value to cover closing costs like legal fees, insurance, and adjustments. If you’ve managed to save this on your own, that’s a great sign of financial discipline. If you're receiving help from a family member through a gifted down payment , that works too—as long as the paperwork is in order. Either way, having these funds ready shows you’re prepared for the upfront costs of homeownership. 2. Your Credit Profile Tells a Good Story Lenders want to know how you manage debt. Before they approve you for a mortgage, they’ll review your credit history. What they typically like to see: At least two active credit accounts (trade lines) , like a credit card or loan Each with a minimum limit of $2,000 Open and active for at least 2 years Even if your credit isn’t perfect, don’t panic. There may still be options, such as using a co-signer or working on a credit improvement plan with a mortgage expert. 3. Your Income Can Support Homeownership—Comfortably A steady income is essential, but not all income is treated equally. If you’re full-time and past probation , you’re in a strong position. If you’re self-employed, on contract, or rely on variable income like tips or commissions, you’ll generally need a two-year history to qualify. A general rule: housing costs (mortgage, taxes, utilities) should stay under 35% of your gross monthly income . That leaves plenty of room for other living expenses, savings, and—yes—some fun too. 4. You’ve Talked to a Mortgage Professional Let’s be real—there’s a lot of info out there about buying a home. Google searches and TikToks can only take you so far. If you're serious about buying, speaking with a mortgage professional is the most effective next step. Why? Because you'll: Get pre-approved (and know what price range you're working with) Understand your loan options and the qualification process Build a game plan that suits your timeline and financial goals The Bottom Line: Being “ready” to buy a home isn’t just about how much you want it—it’s about being financially prepared, credit-ready, and backed by expert advice. If you’re thinking about homeownership, let’s chat. I’d love to help you understand your options, crunch the numbers, and build a plan that gets you confidently across the finish line—keys in hand.