The 32/39 rule is the lender’s budget test: your housing costs should stay under 32% of your gross income (the GDS ratio), and housing plus all your other debt payments should stay under 39% (the TDS ratio). Pass both, and the income side of your application works. Fail either one, and the mortgage shrinks until you pass.

These two percentages quietly decide more Edmonton approvals than any other numbers in the file. Here’s exactly how they’re calculated — with a real budget.

GDS: the housing-cost ratio

Gross Debt Service ratio = (mortgage payment + property tax + heating cost + 50% of condo fees) ÷ gross monthly income

Key details borrowers miss:

• The mortgage payment is calculated at the stress-test qualifying rate, not your actual rate — the higher of your contract rate + 2% or the 5.25% benchmark. That’s why our mortgage stress test explainer matters to this math: https://nextdoormortgages.com/general/mortgage-stress-test-explained-qualifying-rate-edmonton/
• Property tax is your actual annual tax divided by 12 — in Edmonton, roughly $260–$330/month on a mid-priced detached home.
• Heating is usually a standardized estimate, commonly $100/month for a house.
• Only half of condo fees count in GDS — but as the worked example below shows, half is still plenty.

TDS: the everything ratio

Total Debt Service ratio = (all GDS costs + every other debt payment) ÷ gross monthly income

“Every other debt payment” means the minimum or contractual payments on car loans and leases, credit cards (assessed at 3% of the balance, not your actual payment), student loans, lines of credit (typically assessed at 3% of balance too), and any support payments. Lenders don’t use what you usually pay — they use their formula, and the formula is not generous.

The worked Edmonton budget

Meet our example buyers: a household earning $110,000/year ($9,167/month gross), no debts, looking at a $450,000 Edmonton detached home with 10% down.

• Mortgage: $405,000 + CMHC premium (2.80% at 90% LTV ≈ $11,340) ≈ $416,340
• Tested payment at a 6.50% qualifying rate (example): about $2,790/month
• Property tax: about $300/month
• Heat: $100/month
• GDS total: $3,190 ÷ $9,167 = 34.8%

Against the classic 32% rule, this file fails. Against the extended ratios insurers allow on strong insured files (35% GDS / 44% TDS), it passes. Same house, same income, same buyers — the rulebook decides. Now add a $480/month vehicle payment:

• TDS total: ($3,190 + $480) ÷ $9,167 = 40.0%

That busts the classic 39% TDS but fits the extended 44%. This is the single most common pattern I see in Edmonton: a household that qualifies for the house, right up until the truck payment enters the spreadsheet.

Photo via Wikimedia Commons

Now the condo version — where fees bite

Same $110,000 household, now buying a $290,000 apartment condo with 10% down and $390/month condo fees.

• Mortgage: $261,000 + premium ≈ $268,300; tested payment about $1,797/month
• Property tax: about $185/month; heat: $50/month (smaller unit)
• Condo fees in GDS: 50% × $390 = $195/month
• GDS total: $2,227 ÷ $9,167 = 24.3% — passes easily

Cheaper homes leave ratio room to spare, which is why condo files so often survive a car payment that kills a detached file. Run the same condo at a $72,000 income ($6,000/month) and GDS jumps to 37% — a fail almost everywhere. Price-to-income fit is the whole game.

Are 32/39 hard rules?

They’re guidelines with documented flexibility, and the flexibility has rules of its own:

• Insured mortgages (less than 20% down) with a credit score of 680+ can be approved up to 35/44 by the insurers. Below that credit score, you’re held closer to the classic numbers — one more reason the down payment and credit file interact, as covered in how much down payment you need in Canada: https://nextdoormortgages.com/general/how-much-down-payment-canada-insured-uninsured/
• Uninsured mortgages (20%+ down) are underwritten lender by lender; strong files with big equity sometimes stretch slightly past 39% TDS, weak ones get cut below it.
• B lenders publish higher ratio ceilings — sometimes 50%+ TDS — priced accordingly.

What never flexes: the direction. Every dollar of monthly debt payment you carry is a dollar that can’t go to housing, at roughly a 150-to-1 exchange rate against mortgage size (a $100/month payment ≈ $15,000 of mortgage at today’s qualifying rates, as an example calculation).

Three moves that fix a failed ratio

1. Kill the smallest debts first. A $95/month store-card payment blocks about $14,000 of mortgage. Paying it off entirely beats adding the same cash to your down payment, almost every time.
2. Re-shop the property taxes. On the same income, a home with lower taxes (newer Edmonton subdivisions vs. some mature areas can differ by $1,000+/year) quietly raises what you qualify for.
3. Pick the lender whose rulebook fits. Ratio ceilings, condo-fee treatment, and line-of-credit assessment vary. Posted rates are a starting point and rates are sometimes negotiable — but the lender with the best rate and the wrong ratio treatment still says no. I work with multiple lenders precisely so your file goes to the rulebook that fits it, and we’ll shop your rate across them once it does.

Check your own two numbers

Bring your income, your debts, and a target price to our free Pre-Approval & Refinance Check: https://nextdoormortgages.com/pre-approval-refinance-check/ and I’ll run your exact GDS and TDS — at the classic and extended ratios — and tell you which lenders your budget passes today. Call Travis Bannert, Mortgage Broker with Next Door Mortgages, BFL Dominion Lending Centres, at 780-720-8240.

FAQ

What is a good GDS and TDS in Canada? The classic underwriting targets are 32% GDS and 39% TDS. Insured files with credit scores of 680+ can often be approved up to 35% and 44%. Lower is always safer — and cheaper in life, not just on paper.

Do lenders use my actual mortgage payment in the ratios? No. They use your payment calculated at the stress-test qualifying rate — contract rate + 2%, or the 5.25% benchmark, whichever is higher. Your tested payment is higher than your real one.

Why does only half my condo fee count? Because part of a condo fee covers things like exterior insurance and reserves that aren’t personal shelter costs. Lenders split the difference at 50% — but on a high-fee building, that half can still decide the file.

Can I be approved if I’m slightly over 39% TDS? Sometimes, on an insured file with strong credit (up to 44%) or an uninsured file with large equity. “Slightly over” is a lender-selection problem, not an automatic no — which is why the file should be shopped, not surrendered.

Want me to walk you through it? Call Travis Bannert at 780-720-8240 — I will try to call you this week; reply with a good time and we will set a phone appointment to run your exact GDS and TDS before you shop.

By Travis Bannert, Realtor and Mortgage Broker

Travis Bannert, Mortgage Broker | Next Door Mortgages, BFL Dominion Lending Centres | 780-720-8240 | nextdoormortgages.com

Photos via Wikimedia Commons.