What You Need To Know About Online Mortgage Calculators

Tanya Toye • November 20, 2024

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.


Tanya Toye

Mortgage Broker

GET STARTED
By Tanya Toye August 13, 2025
Can You Afford That Mortgage? Let’s Talk About Debt Service Ratios One of the biggest factors lenders look at when deciding whether you qualify for a mortgage is something called your debt service ratios. It’s a financial check-up to make sure you can handle the payments—not just for your new home, but for everything else you owe as well. If you’d rather skip the math and have someone walk through this with you, that’s what I’m here for. But if you like to understand how things work behind the scenes, keep reading. We’re going to break down what these ratios are, how to calculate them, and why they matter when it comes to getting approved. What Are Debt Service Ratios? Debt service ratios measure your ability to manage your financial obligations based on your income. There are two key ratios lenders care about: Gross Debt Service (GDS) This looks at the percentage of your income that would go toward housing expenses only. 2. Total Debt Service (TDS) This includes your housing costs plus all other debt payments—car loans, credit cards, student loans, support payments, etc. How to Calculate GDS and TDS Let’s break down the formulas. GDS Formula: (P + I + T + H + Condo Fees*) ÷ Gross Monthly Income Where: P = Principal I = Interest T = Property Taxes H = Heat Condo fees are usually calculated at 50% of the total amount TDS Formula: (GDS + Monthly Debt Payments) ÷ Gross Monthly Income These ratios tell lenders if your budget is already stretched too thin—or if you’ve got room to safely take on a mortgage. How High Is Too High? Most lenders follow maximum thresholds, especially for insured (high-ratio) mortgages. As of now, those limits are typically: GDS: Max 39% TDS: Max 44% Go above those numbers and your application could be declined, regardless of how confident you feel about your ability to manage the payments. Real-World Example Let’s say you’re earning $90,000 a year, or $7,500 a month. You find a home you love, and the monthly housing costs (mortgage payment, property tax, heat) total $1,700/month. GDS = $1,700 ÷ $7,500 = 22.7% You’re well under the 39% cap—so far, so good. Now factor in your other monthly obligations: Car loan: $300 Child support: $500 Credit card/line of credit payments: $700 Total other debt = $1,500/month Now add that to the $1,700 in housing costs: TDS = $3,200 ÷ $7,500 = 42.7% Uh oh. Even though your GDS looks great, your TDS is just over the 42% limit. That could put your mortgage approval at risk—even if you’re paying similar or higher rent now. What Can You Do? In cases like this, small adjustments can make a big difference: Consolidate or restructure your debts to lower monthly payments Reallocate part of your down payment to reduce high-interest debt Add a co-applicant to increase qualifying income Wait and build savings or credit strength before applying This is where working with an experienced mortgage professional pays off. We can look at your entire financial picture and help you make strategic moves to qualify confidently. Don’t Leave It to Chance Everyone’s situation is different, and debt service ratios aren’t something you want to guess at. The earlier you start the conversation, the more time you’ll have to improve your numbers and boost your chances of approval. If you're wondering how much home you can afford—or want help analyzing your own GDS and TDS—let’s connect. I’d be happy to walk through your numbers and help you build a solid mortgage strategy.
By Tanya Toye August 6, 2025
If you're looking to buy a new property, refinance, or renew an existing mortgage, chances are, you're considering either a fixed or variable rate mortgage. Figuring out which one is the best is entirely up to you! So here's some information to help you along the way. Firstly, let's talk about the fixed-rate mortgage as this is most common and most heavily endorsed by the banks. With a fixed-rate mortgage, your interest rate is "fixed" for a certain term, anywhere from 6 months to 10 years, with the typical term being five years. If market rates fluctuate anytime after you sign on the dotted line, your mortgage rate won't change. You're a rock; your rate is set in stone. Typically a fixed-rate mortgage has a higher rate than a variable. Alternatively, a variable rate is not set in stone; instead, it fluctuates with the market. The variable rate is a component (either plus or minus) to the prime rate. So if the prime rate (set by the government and banks) is 2.45% and the current variable rate is Prime minus .45%, your effective rate would be 2%. If three months after you sign your mortgage documents, the prime rate goes up by .25%, your rate would then move to 2.25%. Typically, variable rates come with a five-year term, although some lenders allow you to go with a shorter term. At first glance, the fixed-rate mortgage seems to be the safe bet, while the variable-rate mortgage appears to be the wild card. However, this might not be the case. Here's the problem, what this doesn't account for is the fact that a fixed-rate mortgage and a variable-rate mortgage have two very different ways of calculating the penalty should you need to break your mortgage. If you decide to break your variable rate mortgage, regardless of how much you have left on your term, you will end up owing three months interest, which works out to roughly two to two and a half payments. Easy to calculate and not that bad. With a fixed-rate mortgage, you will pay the greater of either three months interest or what is called an interest rate differential (IRD) penalty. As every lender calculates their IRD penalty differently, and that calculation is based on market fluctuations, the contract rate at the time you signed your mortgage, the discount they provided you at that time, and the remaining time left on your term, there is no way to guess what that penalty will be. However, with that said, if you end up paying an IRD, it won't be pleasant. If you've ever heard horror stories of banks charging outrageous penalties to break a mortgage, this is an interest rate differential. It's not uncommon to see penalties of 10x the amount for a fixed-rate mortgage compared to a variable-rate mortgage or up to 4.5% of the outstanding mortgage balance. So here's a simple comparison. A fixed-rate mortgage has a higher initial payment than a variable-rate mortgage but remains stable throughout your term. The penalty for breaking a fixed-rate mortgage is unpredictable and can be upwards of 4.5% of the outstanding mortgage balance. A variable-rate mortgage has a lower initial payment than a fixed-rate mortgage but fluctuates with prime throughout your term. The penalty for breaking a variable-rate mortgage is predictable at 3 months interest which equals roughly two and a half payments. The goal of any mortgage should be to pay the least amount of money back to the lender. This is called lowering your overall cost of borrowing. While a fixed-rate mortgage provides you with a more stable payment, the variable rate does a better job of accommodating when "life happens." If you’ve got questions, connect anytime. It would be a pleasure to work through the options together.