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.
See it on a real file: Grande Prairie Oilfield Owner's First Home →
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 files. Names and identifying details removed.
- Case study · Residential / AlternativeBuying Out a Half Owner in Maple Ridge: An Alternative-Lender Refinance at 70% on Homestay and Suite IncomeBuying out a half owner on one fixed salary and non-taxable homestay income with no pay stubs: an alternative lender refinanced the Maple Ridge house at 70% in 2021, $1,050,000, grossing the homestay and child benefit up 25%.Read the file →
- Case study · Residential / PrimeRideshare Income and 10% Down: A Major Bank's Insured Mortgage Bought a First Condo in Delta at 90%A self-employed rideshare driver and a draftsperson bought their first home, a Delta condo, at 90% in 2024 with a major Canadian bank's insured mortgage, $432,000 plus the premium at about 4.8%, the driving income averaged over two years and grossed up by 15%.Read the file →
- Case study · Residential / PrimeRatios Near 46% and a Job Under a Year Old: A Major Bank Financed a First Home With a Suite in Delta at 80%A first-time couple with ratios near 46% and one job under a year old bought a five-bedroom Delta home with a suite at 80% in 2025, $1,118,400 at 4.55% from a major Canadian bank, helped by a $160,000 gift from a parent.Read the file →
More case studies that use this calculator (32)
- Assignment Rental on Commission and Tips
- 574 Score, Stated-Income Townhouse
- Six Years From Presale Deposit to Keys
- Single Parent's Estate-Sale Townhouse
- Presale Completed on a Private Open Term
- Realtor Moves to Ontario: Burlington at 45%
- Restaurant Owner's First Condo at 80%
- Sold in Surrey, Bought in Edmonton Next Day
- First Home at 95% With a Parent's Gift
- First Home on Business Bank Statements
- Rental Bought on a Work Permit at 80%
- Part-Time by Choice, Condo Bought at 50%
- Two Households, One Maple Ridge Acreage
- Foster-Care Income Counted at a Bank
- Foster Family's 8-Bedroom Home at 50% LTV
- Leasehold Condo First Home, Insured at 90%
- Alberta Presale on a Private Open Mortgage
- Presale Carried on an Open Private Mortgage
- Buying Before the Presale Sold, Inter Alia
- Ontario Refinance at 75% Funded the Presale
- 487% Gross-Up for a Coquitlam Lawyer's First Home
- 181.5% Gross-Up for a Realtor's First Home
- New PRs, New Jobs, First Home at 65%
- Grande Prairie Oilfield Owner's First Home
- Bankruptcy Behind Them, Alberta Purchase
- Two Private Mortgages to an A Lender
- Alberta Presale Approved on Net Worth
- Officers Approved Despite a Past Bankruptcy
- Officer Buys a Townhouse, Keeps the Condo
- Net Worth Mortgage After a Separation
- Physician From the U.S., No Canadian Credit
- Buying a Home Mid-Separation, Still on a Joint Mortgage
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: GDS / TDS for a mortgage you have in mind → · 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 October 18, 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.