GDS/TDS Ratios Explained

Joe Tomkins • August 21, 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.


JOE TOMKINS
MORTGAGE BROKER

CONTACT ME
By Joe Tomkins October 30, 2025
Buying a property might actually be easier than you think. So, if you have NO desire AT ALL to qualify for a mortgage, here are some great steps you can take to ensure you don’t accidentally buy a property. Fair warning, this article might get a little cheeky. Quit your job. First things first, ditch that job. One of the best ways to make sure you won’t qualify for a mortgage is to be unemployed. Yep, most mortgage lenders aren’t in the practice of lending money to unemployed people! If you already have a preapproval in place and don’t want to go through with financing, no problems. Unexpectedly quit your job mid-application. Because, even if you’re making a lateral move or taking a better job, any change in employment status can negatively impact your approval. Spend All Your Savings. To get a mortgage, you’ll have to bring some money to the table. In Canada, the minimum downpayment required is 5% of the purchase price. Now, if the goal is not to get a mortgage, spending all your money and having absolutely nothing in your account is a surefire way to ensure you won’t qualify for a mortgage. So, if you’ve been looking for a reason to go out and buy a new vehicle, consider this your permission. Collect as Much Debt as Possible. After quitting your job and spending all your savings, you should definitely go out and incur as much debt as possible! The higher the payments, the better. You see, one of the main qualifiers on a mortgage is called your debt-service ratio. This takes into count the amount of money you make compared to the amount of money you owe. So the more debt you have, the less money you’ll have leftover to finance a home. Stop Making Your Debt Payments So let’s say you can’t shake your job, you still have a good amount of money in the bank, and you’ve run out of ways to spend money you don’t have. Don’t panic; you can still absolutely wreck your chances of qualifying for a mortgage! Just don’t pay any of your bills on time or stop making your payments altogether. Why would any lender want to lend you money when you have a track record of not paying back any of the money you’ve already borrowed? Provide Ugly Supporting Documentation. Now, if all else fails, the last chance you have to scuttle your chances of getting a mortgage is to provide the lender with really ugly documents. To support your mortgage application, lenders must complete their due diligence. Here are three ways to make sure the lender won’t be able to verify anything. Firstly, and probably the most straightforward, make sure your name doesn’t appear anywhere on any of your statements. This way, the lender can’t be sure the documents are actually yours or not. Secondly, when providing bank statements to prove downpayment funds, make sure there are multiple cash deposits over $1000 without explaining where the money came from. This will look like money laundering and will throw up all kinds of red flags. And lastly, consider blacking out all your “personal information.” Just use a black Sharpie and make your paperwork look like classified FBI documents. Follow-Through So there you have it, to avoid an accidental home purchase, you should quit your job, spend all your money, borrow as much money as possible, stop making your payments, and make sure the lender can’t prove anything! This will ensure no one will lend you money to buy a property! Now, on the off chance that you’d actually like to qualify for a mortgage, you’ve come to the right place. The suggestion would be to actually keep your job, save for a downpayment, limit the amount of debt you carry, make your payments on time, and provide clear documentation to support your mortgage application! If you'd like to make sure you're on the right track, connect anytime. It would be a pleasure to walk through the mortgage process with you.
By Joe Tomkins October 16, 2025
A no-frills service or product is where non-essential features have been removed from the product or service to keep the price as low as possible. And while keeping costs low at the expense of non-essential features might be okay when choosing something like which grocery store to shop at, which economy car to purchase, or which budget hotel to spend the night, it’s not a good idea when considering which lender to secure mortgage financing. Here’s why. When securing mortgage financing, your goal should be to pay the least amount of money over the term. Your plan should include having provisions for unexpected life changes. Unlike the inconvenience of shopping at a store that doesn’t provide free bags, or driving a car without power windows, or staying at a hotel without any amenities, the so-called “frills” that are stripped away to provide you with the lowest rate mortgage are the very things that could significantly impact your overall cost of borrowing. Depending on the lender, a “no-frills” mortgage rate might be up to 0.20% lower than a fully-featured mortgage. And while this could potentially save you a few hundreds of dollars over a 5-year term, please understand that it could also potentially cost you thousands (if not tens of thousands) of dollars should you need to break your mortgage early. So if you’re considering a “no-frills” mortgage, here are a few of the drawbacks to think through: You'll pay a significantly higher penalty if you need to break your mortgage. You'll have limited pre-payment privileges. Potential limitations if you want to port your mortgage to a different property. You might be limited in your ability to refinance your mortgage (without incurring a considerable penalty). Simply put, a “no-frills” mortgage is an entirely restrictive mortgage that leaves you without any flexibility. There are many reasons you might need to keep your options open. You might need to break your term because of a job loss or marital breakdown, or maybe you decide to take a new job across the country, or you need to buy a property to accommodate your growing family. Life is unpredictable; flexibility matters. So why do banks offer a no-frills mortgage anyway? Well, when you deal with a single bank or financial institution, it’s the banker’s job to make as much money from you as possible, even if that means locking you into a very restrictive mortgage product by offering a rock bottom rate. Banks know that 2 out of 3 people break their mortgage within three years (33 months). However, when you seek the expert advice of an independent mortgage professional, you can expect to see mortgage options from several institutions showcasing mortgage products best suited for your needs. We have your best interest in mind and will help you through the entire process. A mortgage is so much more than just the lowest rate. If you have any questions about this, or if you’d like to discuss anything else mortgage-related, please get in touch. Working with you would be a pleasure!
By Joe Tomkins October 2, 2025
Deciding to list your home for sale is a big decision. And while there are many reasons you might want/need to sell, here are 3 questions you should ask yourself; and have answers to, before taking that step. What is my plan to get my property ready for sale? Assessing the value of your home is an important first step. Talking with a real estate professional will help accomplish that. They will be able to tell you what comparable properties in your area have sold for and what you can expect to sell your property for. They will also know specific market conditions and be able to help you put a plan together. But as you’re putting together that plan, here are a few discussion points to work through. A little time/money upfront might increase the final sale price. Declutter and depersonalize Minor repairs A fresh coat of interior/exterior paint New fixtures Hire a home stager or designer Exterior maintenance Professional pictures and/or virtual tour But then again, these are all just considerations; selling real estate isn’t an exact science. Current housing market conditions will shape this conversation. The best plan of action is to find a real estate professional you trust, ask a lot of questions, and listen to their advice. What are the costs associated with selling? Oftentimes it’s the simple math that can betray you. In your head, you do quick calculations; you take what you think your property will sell for and then subtract what you owe on your mortgage; the rest is profit! Well, not so fast. Costs add up when selling a home. Here is a list of costs you’ll want to consider. Real estate commissions (plus tax) Mortgage discharge fees and penalties Lawyer’s fees Utilities and property tax account settlements Hiring movers and/or storage fees Having the exact figures ahead of time allows you to make a better decision. Now, the real wildcard here is the potential mortgage penalty you might pay if you break your existing mortgage. If you need help figuring this number out, get in touch! What is my plan going forward? If you’re already considering selling your home, it would be fair to guess that you have your reasons. But as you move forward, make sure you have a plan that is free of assumptions. If you plan to move from your existing property to another property that you will be purchasing, make sure you have worked through mortgage financing ahead of time. Just because you’ve qualified for a mortgage in the past doesn’t mean you’ll qualify for a mortgage in the future. Depending on when you got your last mortgage, a lot could have changed. You’ll want to know exactly what you can qualify for before you sell your existing property. If you’d like to talk through all your options, connect anytime! It would be a pleasure to work with you and provide you with professional, unbiased advice.