Canadian mortgage affordability calculator

"How much home can I afford?" has at least two answers. There's the bank's answer: the largest mortgage they'll approve based on your income, debts, and the OSFI stress test. And there's the planner's answer: the largest mortgage you can actually carry without compromising your retirement savings, vacations, or general sanity.

The gap between those two numbers is bigger than most buyers realize. The calculator above gives you the bank's answer. This guide explains the planner's answer, the rules behind the bank's number, and the levers you can pull to widen the gap in your favour.

What "affordable" actually means in Canada

In 2026, Canada's six major housing markets all rank "severely unaffordable" or worse on the median-multiple test (price-to-income ratio, where 3.0 is considered affordable). Per the Demographia International Housing Affordability 2025 survey:

Vancouver 11.8 (fourth worst globally), Toronto 8.4, Montreal 5.8, Ottawa-Gatineau 5.0, Calgary 4.8, national 5.4. CMHC's benchmark home price was $664,400 in March 2026. CMHC notes affordability has slightly improved since 2023 in Ottawa, Toronto, Vancouver, and Halifax, but most cities remain stretched.

Two answers to "what can I afford":

The bank's answer. Your debt-service ratios at the OSFI stress-test rate, capped at 39% GDS and 44% TDS. This is what the calculator above computes.

The planner's answer. Wealthsimple's guidance is to "keep housing costs under 28-35% of gross income for financial comfort. Affordability isn't about the maximum amount a bank will lend you, it's about how much you can comfortably part with every 30 days without feeling strained." Ratehub frames it as a sliding range: GDS 32% as the comfort line below the 39% maximum.

A useful shorthand: lenders say yes at 39%/44%; planners say live around 32%/40%. The calculator above gives you the lender max. Take 5-10 percentage points off and you've got the planner number.

GDS and TDS, in plain English

GDS and TDS are the two ratios that decide everything else.

Gross debt service (GDS) is your monthly housing costs (mortgage payment + property tax + heat + 50% of any condo fees) divided by gross monthly income. Capped at 39%.

Total debt service (TDS) is your GDS plus all other monthly debt obligations (car loans, credit cards, student loans, lines of credit, child support) divided by gross monthly income. Capped at 44%.

CMHC's underwriting page is the authoritative source. The 39%/44% limits replaced an older 35%/42% in July 2021 and are now uniform across CMHC, Sagen, and Canada Guaranty.

What's NOT in TDS: rent (you're moving out), groceries, hydro and water, internet, transportation other than the car loan itself, kids' activities, restaurant meals, or anything else discretionary. The bank doesn't see those. They might still bury you, but they won't fail your application.

The stress test, where the gap really shows

OSFI's qualifying-rate rule is a single sentence with massive consequences: when your bank decides what you can afford, they apply your debt-service ratios at the greater of (your contract rate + 2 percentage points) or 5.25%, not at the rate you actually pay.

OSFI's stated purpose: "This helps lenders prepare borrowers so they can continue to make mortgage payments even if they experience negative financial shocks such as a reduction in income, an increase in household expenses, or an increase in mortgage interest rates." The Bank of Canada confirmed in Staff Analytical Note 2024-25 that the test "improves credit quality, reduces credit growth and house price growth, and improves the resilience of borrowers."

This is why the calculator above shows your GDS and TDS at both rates side by side. At the contract rate they're comfortable; at the qualifying rate they hit the limit. The gap is the buffer your income has to absorb if rates ever rise to the qualifying level (and during the 2022-2023 cycle, they did).

The December 2024 reforms

On December 15, 2024, the federal government enacted what it called "the boldest mortgage reforms in decades." Two changes mattered for affordability:

1. 30-year insured amortization is available to first-time home buyers and buyers of newly-built homes (other insured borrowers still cap at 25 years).

2. The insured-mortgage cap rose from $1 million to $1.5 million.

Per CMHC's 2025 Mortgage Consumer Survey, 65% of first-time buyers paid the maximum they could afford in 2025, 41% used family financial gifts averaging $74,570, and 38% used the FHSA. The reforms didn't make houses dramatically cheaper. They let buyers stretch slightly farther with the same income, partly closing the gap that the stress test had widened.

What banks consider income

The calculator asks for "gross household income" because that's what banks use. But not all income is treated equally.

T4 employees with steady jobs are the easiest case: two years of T4s plus recent pay stubs and an employment letter is usually enough.

Self-employed (T1 / NOA filers) typically need two years of personal tax returns (line 15000 of your T1 General) plus business documentation. Banks may gross up legitimate business write-offs by around 15% to estimate "true" income, but most A-lenders are conservative. If your corporation retains earnings (i.e. you pay yourself less than your business actually makes), your personal T1 will understate your real income, and the bank will lend against the smaller number.

Commission earners and T4A contractors are usually averaged over two years; some banks accept one year if you've been in the same industry for longer. The variability discount can reduce qualifying income materially.

Real example from The Globe and Mail (July 2025): Emily (30, self-employed business owner) and Lisa (28) in Edmonton bought a $565,020 home. Major banks approved them for around $450,000 based on Emily's personal T1, because she'd reinvested earnings into her corporation. They went to an alternative lender (Alt-A) that underwrote against corporate income and qualified them up to $800,000. They put 16% down on a 5-year fixed at 4.19% with a 30-year amortization, paying around $2,400 a month. Emily told the paper: "My corporation's income is way greater than my personal one. That allowed us to actually qualify up to $800,000." The trade-off: Alt-A lenders charge a rate premium and require mortgage insurance regardless of down payment.

If your income is non-traditional, the maximum this calculator gives you is your A-lender ceiling. An Alt-A maximum may be higher, but it comes with costs you can't see from a calculator.

How to grow your max

Five concrete levers, in roughly descending order of impact for typical buyers:

1. Reduce monthly debts. Each $100/month of recurring debt (car loan, credit-card minimum, student loan) eats $1,200 of annual debt-service capacity, which translates to roughly $20,000-$30,000 less in mortgage capacity. Pay off a car loan and you can borrow $30K-$50K more for the same income.

2. Increase your down payment. Beyond the dollar-for-dollar increase in home price, pushing past 20% removes the CMHC premium, shifts you to a conventional mortgage (no $1.5M cap), and may unlock 30-year amortization without FTHB / new-build status.

3. Use the 30-year amortization (if you're a first-time buyer or buying new construction). Roughly 8-10% more home price for the same monthly payment, at the cost of more total interest.

4. Lower your contract rate. A one-percentage-point rate reduction is typically worth around 10% more home price at the same payment. Worth shopping the broker channel, since posted rates from Big 6 banks are typically 0.5-2 percentage points above what brokers can offer.

5. Increase income. Direct GDS/TDS impact, but hardest to control short-term. A second income (partner, spouse) is the biggest move; raises and additional contract work are the slow ones.

The calculator lets you change each input and see the max recompute instantly. URL-state persistence means you can save scenarios as bookmarks (or share them with a partner via the "Copy share link" button at the bottom of the form).

Frequently asked questions

What's the difference between what the bank will approve and what I can afford?

The bank approves based on the OSFI stress test (GDS up to 39%, TDS up to 44%, both at the qualifying rate). "What you can afford" without straining your other goals (savings, retirement, family expenses) is typically lower. Wealthsimple recommends 28-35% of gross income on housing; Ratehub recommends GDS around 32%. Take 5-10 percentage points off the calculator's max and you'll be living in the planner's affordable range, not just the bank's.

Why does the calculator show GDS and TDS at two different rates?

The contract rate is what you actually pay each month. The qualifying rate is what the bank tests you against (your contract rate plus 2 percentage points, or the 5.25% floor). Your max home price is determined by the qualifying-rate ratios, but you only ever pay the contract-rate amount. Showing both makes the gap concrete: the contract-rate ratios are comfortable, the qualifying-rate ratios are at the limit, and the difference is the rate-rise buffer your income has to support to be approved.

I'm self-employed. Will this calculator work for me?

Sort of. The calculator computes your A-lender (Big 6 bank) maximum based on whatever income figure you enter. The catch is that banks often won't lend against your full self-employed income; they want to see line 15000 of your T1, which excludes earnings retained in a corporation. If your personal T1 income is much lower than your business's actual cash flow, you'll have a real gap with what an alternative lender (Alt-A) might offer. Speak with a broker who works with both A-lenders and Alt-A to see your true range.

Should I take the 30-year amortization to afford more?

Maybe. Five extra years of amortization typically saves around $260/month on a typical insured mortgage but adds about $65,000 in lifetime interest. If the $260/month would let you also save into an RRSP / TFSA / FHSA at a meaningful rate, the math could come out ahead. If you'd just spend it, the 25-year option is cheaper overall. The 30-year option is most useful when it's the difference between buying and not buying, not when you're choosing between two homes you could afford either way.

How does the bank verify my income?

T4 employees: two years of T4s, recent pay stubs, and an employment letter. Self-employed: two years of T1 General returns, two years of NOAs, and business financial statements (or unincorporated business records). Commission / T4A: two-year averages of the relevant income. Banks also pull credit bureau reports and confirm any mortgage statement, line-of-credit balance, and credit-card balance. They cross-check disclosed monthly debts against the bureau.

Why isn't rent in my TDS?

Banks treat affordability as forward-looking: when you buy, you stop renting. So the TDS you'll be assessed on is your post-purchase debt service, not your current cost of living. The calculator follows the same convention. Practically: if your current rent is much lower than the new mortgage payment, your post-purchase budget squeeze will be larger than the GDS / TDS numbers suggest. Use the planner threshold (32% GDS / 40% TDS) to leave yourself room.

How do family gifts affect what I can afford?

Family gifts, treated as a traditional source of down payment (with a signed gift letter), increase your down payment dollar-for-dollar without affecting your debt-service ratios. Per CMHC's 2025 Mortgage Consumer Survey, 41% of first-time buyers used family gifts averaging $74,570. A $75,000 gift increases your home-price ceiling by exactly $75,000 (plus the leverage effect of having a smaller mortgage). Just have the gift letter ready: lenders verify it.

Where do CalcNorth's numbers come from?

Math: bisection over home price subject to GDS ≤ 39% and TDS ≤ 44% at the OSFI qualifying rate, with CMHC eligibility (5%/10% staircase, $1.5M cap, 95% LTV ceiling) checked at every probed price. Sources: CMHC's published GDS/TDS guidelines, OSFI's Minimum Qualifying Rate, the Bank of Canada's Valet API for rate context, and provincial revenue authorities for land transfer tax. Verified against CMHC's reference and the Globe and Mail's Edmonton-couple worked example to the cent.