What Are GDS/TDS Ratios Anyways?

Diane Gogar • September 13, 2023

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.


DIANE GOGAR
MORTGAGE PROFESSIONAL
CONTACT ME

What You Need To Know About Online Mortgage Calculators

By Diane Gogar • May 28, 2025
You’d think an online calculator is a pretty straightforward device, one that you should be able to place your confidence in, and for the most part, they are. Calculators calculate numbers. The numbers are reliable, but how you interpret those numbers, not so much, especially if the goal is mortgage qualification. If you rely on the numbers from a “What can I afford” or “Mortgage Qualification” calculator without talking to an independent mortgage professional, you’re going to be misinformed. Don’t be fooled. Even though an online mortgage calculator can help you calculate mortgage payments or help you assess how additional payments would impact your amortization, they’ll never be able to give you an exact picture of what you can afford and how a lender will consider your mortgage application. While mortgage calculators are objective, mortgage lending isn’t. It’s 100% subjective. Lenders consider your financial situation, employment, credit history, assets, liabilities, the property you are looking to purchase. Then, they will compare that with whatever internal risk profile they are currently using to assess mortgage lending. Simply put, they don’t just look at the numbers. An online calculator is a great tool to help you run different financial scenarios and help assess your comfort level with different payment schedules and mortgage amounts. However, if you rely on an online calculator for mortgage qualification purposes, you’ll be disappointed. The first step in the mortgage qualification process is a preapproval. A preapproval will examine all the variables on your application, assess your financial situation, and provide you with a framework to buy a property based on your unique circumstance. Securing a preapproval comes at no cost to you and without any obligation to buy. It’ll simply allow you the freedom to move ahead with confidence, knowing exactly where you stand. Something a calculator is unable to do. Please connect anytime if you’d like to talk more about your financial situation and get a preapproval started. It would be a pleasure to work with you.

Going Through A Divorce? Protect your Credit

By Diane Gogar • May 21, 2025
Divorces are challenging as there’s a lot to think about in a short amount of time, usually under pressure. And while handling finances is often at the forefront of the discussions related to the separation of assets, unfortunately, managing and maintaining personal credit can be swept aside to deal with later. So, if you happen to be going through or preparing for a divorce or separation, here are a few considerations that will help keep your credit and finances on track. The goal is to avoid significant setbacks as you look to rebuild your life. Manage Your Joint Debt If you have joint debt, you are both 100% responsible for that debt, which means that even if your ex-spouse has the legal responsibility to pay the debt, if your name is on the debt, you can be held responsible for the payments. Any financial obligation with your name on the account that falls into arrears will negatively impact your credit score, regardless of who is legally responsible for making the payments. A divorce settlement doesn’t mean anything to the lender. The last thing you want is for your ex-spouse’s poor financial management to negatively impact your credit score for the next six to seven years. Go through all your joint credit accounts, and if possible, cancel them and have the remaining balance transferred into a loan or credit card in the name of whoever will be responsible for the remaining debt. If possible, you should eliminate all joint debts. Now, it’s a good idea to check your credit report about three to six months after making the changes to ensure everything all joint debts have been closed and everything is reporting as it should be. It’s not uncommon for there to be errors on credit reports. Manage Your Bank Accounts Just as you should separate all your joint credit accounts, it’s a good idea to open a checking account in your name and start making all deposits there as soon as possible. You’ll want to set up the automatic withdrawals for the expenses and utilities you’ll be responsible for going forward in your own account. At the same time, you’ll want to close any joint bank accounts you have with your ex-spouse and gain exclusive access to any assets you have. It’s unfortunate, but even in the most amicable situations, money (or lack thereof) can cause people to make bad decisions; you want to protect yourself by protecting your assets. While opening new accounts, chances are your ex-spouse knows your passwords to online banking and might even know the pin to your bank card. Take this time to change all your passwords to something completely new, don’t just default to what you’ve used in the past. Better safe than sorry. Setup New Credit in Your Name There might be a chance that you’ve never had credit in your name alone or that you were a secondary signer on your ex-spouse’s credit card. If this is the case, it would be prudent to set up a small credit card in your name. Don’t worry about the limit; the goal is to get something in your name alone. Down the road, you can change things and work towards establishing a solid credit profile. If you have any questions about managing your credit through a divorce, please don’t hesitate to connect anytime. It would be a pleasure to work with you.