Mortgage Affordability Calculator
How much mortgage you actually qualify for under the OSFI B-20 stress test — using real Canadian lender math (GDS 39%, TDS 44%, semi-annual compounding).
How lenders count these: car loan = actual payment; credit cards + unsecured personal LOC = 3% of balance each; student loan = 1–1.5% of balance even on a $0 plan.
Heat: CMHC standard $100/mo. Condo: only 50% counts toward your housing ratio.
Qualified at 6.50% (OSFI B-20 stress test).
Two ways to buy
Same income, same down payment — two strategies. Insured pricing assumed ~0.25% below conventional.
Limited by 20% down rule — extra income capacity is unused.
Limited by income — your cash covers more than the minimum down at this price.
- Models liabilities the way lenders actually do: credit cards at 3% of balance, student loans at 1–1.5% of balance even on $0 payment plans
- A multi-property builder that applies 100% rental add-back to income and full carrying costs to TDS — portfolio buyers get real numbers
- Compares insured vs conventional side by side, netting the CMHC premium saved against the extra interest of the higher conventional rate
- Discloses the exception ratios brokers actually place files at: A-lenders to 50/50, alternative lenders to 60/60 — numbers no bank calculator will print
Contract vs stress-test payment
Lenders qualify you on the taller bar — even though you actually pay the shorter one. That's the OSFI B-20 stress test in one picture.
Get your real mortgage approval amount
Every file is different — rental addbacks, lender exceptions, and alternative-lender stretch policies vary case by case. We'll run your exact scenario and tell you precisely what you qualify for.
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Exceptions — you may qualify for more▾
- • Conventional (A-lender) — strong files: as an exception, may be considered up to 50% / 50% GDS / TDS.
- • Alt-lender (minimum 20% down): up to 60% / 60%, and even higher at ≤65% LTV.
- • Insured deals (< 20% down): hard capped at 39% / 44% — no exceptions.
This calculator shows the standard 39/44 case. Exceptions depend on file strength and lender — get in touch to find out your true qualification.
Common questions
What is the Canadian mortgage stress test?+
OSFI's B-20 guideline requires federally-regulated lenders to qualify you at the higher of your contract rate plus 2 percentage points, or 5.25% — whichever is greater. You get the lower contract rate, but the lender uses the higher rate to make sure you could still afford it.
What are GDS and TDS ratios?+
Gross Debt Service (GDS) is mortgage P&I + property tax + heat + 50% of condo fees, divided by gross income — must be 39% or less. Total Debt Service (TDS) adds all other debt payments and must be 44% or less.
Does this work for self-employed income?+
Use your two-year average net income (line 23600 on your T1; self-employed business income comes from your T2125). Some lenders will gross up self-employed income by 15% if you can document a stable two-year history; others want net only. The calculator uses whatever number you enter.
Why does the calculator use semi-annual compounding?+
Canadian fixed-rate mortgages conventionally compound semi-annually — the Interest Act (section 6) requires a blended-payment mortgage's rate to be disclosed calculated yearly or half-yearly, and half-yearly (semi-annual) is the near-universal lender convention. The payment numbers here match what a Canadian lender will quote you.
Case Studies — files like this
Anonymized case studies from our desk. Names and identifying details removed.
How qualifying works: the stress test rate = max(contract rate + 2%, 5.25%). Your lender qualifies you at that higher rate but you pay at the lower contract rate — that gap is your built-in cushion against future rate hikes.
Also see: Mortgage insurance (CMHC) → · Prepayment / payoff → · Land transfer tax →
Every calculator here is built on published Canadian government rules and lender methodology, and was last checked for accuracy on August 1, 2026 — the arithmetic re-verified and every page re-read on screen. Rates and thresholds change — we confirm the current numbers for your file before you rely on them.