Affordability & Requalification Calculator
Renewing, refinancing, or buying? See if you pass the OSFI B-20 stress test — and what the max mortgage is under Canadian qualifying rules at 2026 rates.
Affordability & Requalification Calculator
Check your GDS, TDS, and max mortgage under OSFI B-20 stress test rules.
You qualify up to $593,476 under the stress test. A broker can find lenders with best ratio flexibility.
A broker will confirm this with real lender quotes — for free.
How the OSFI B-20 Stress Test Works
Since 2018, every federally regulated Canadian mortgage lender (Big 6 banks plus most monolines — First National, MCAP, CMLS, Strive, RFA, Equitable Bank) must qualify borrowers at the qualifying rate, which is the greater of:
- The contract rate + 2%, or
- A 5.25% floor
At today's market rate of ~4.29%, the qualifying rate is 6.29%. At a 5.50% contract rate, it jumps to 7.50%. You must show that your debt ratios (GDS and TDS) stay within OSFI limits at this higher, hypothetical rate — even though your actual payment is at the contract rate.
The November 2024 OSFI update removed this requirement for uninsured straight-switch renewals. If you're moving from one federally regulated lender to another at renewal, with the same balance and same or shorter amortization, no stress test applies. This was a major win for borrowers who would otherwise have been trapped with their existing lender.
GDS & TDS Ratios Explained
Gross Debt Service (GDS) = (P + I + Property Tax + Heat + 50% Condo Fees) ÷ Gross Monthly Income. OSFI caps insured mortgages at 39%. Uninsured lenders typically use 35–39%.
Total Debt Service (TDS) = GDS numerator + all other monthly debt payments (car loan, credit card minimum, line of credit minimum, student loan, spousal/child support). OSFI caps insured mortgages at 44%. Uninsured lenders typically use 42–44%.
Note: credit card and LOC debts are calculated at their minimum payment, which is usually 3% of balance on unsecured lines. Revolving debts you've paid off but not closed still count at the full limit × 3% at some lenders, so close old cards before applying if you can.
When This Calculator Applies
- Buying a new home — full stress test applies
- Refinancing / cash-out refi — full stress test applies because it's "new money"
- Extending amortization at renewal — stress test applies (no longer a "straight switch")
- Adding a co-borrower at renewal — stress test applies
- Changing from insured to uninsured — stress test applies
When the Stress Test Is Waived
- Uninsured straight-switch renewal — same balance, same or shorter amortization, no new money (per Nov 2024 OSFI update)
- Insured-to-insured transfers — mortgage insurance travels with the borrower, no requalification
- Credit union renewals / new mortgages — provincially regulated, can waive internally
- Private / MIC / B lender — not OSFI-bound, use their own internal guidelines
Caveats & Real-World Differences
Our calculator uses OSFI insured limits (39/44). Uninsured lenders often tighten these (35/42) in rising-rate environments. Some lenders add rent-payment equivalents if you're moving from a rental, and some apply a higher deemed rate on variable rate applications. Self-employed applicants use "stated income" programs with different rules entirely. For a personalised qualification estimate, speak with a licensed broker who can run scenarios against multiple lenders' internal guidelines.
Frequently Asked Questions
What are GDS and TDS in Canadian mortgage qualification? +
GDS (Gross Debt Service ratio) is housing costs divided by gross monthly income. Housing costs = principal + interest + property tax + heat (+ 50% of condo fees, if applicable). TDS (Total Debt Service) adds all other debt obligations on top: car loans, credit card minimums, student loans, line of credit minimums. OSFI B-20 caps insured mortgages at 39% GDS and 44% TDS. Uninsured lenders typically use similar limits.
Do I need to requalify at renewal under the stress test? +
Since November 21, 2024, OSFI waives the stress test on uninsured straight-switch renewals — same balance, same or shorter amortization, no new money. If you're taking cash out, extending amortization, or adding a borrower, you must requalify at the stress-test qualifying rate (greater of contract + 2% or 5.25%).
What qualifying rate applies to renewals in 2026? +
For straight-switch renewals at the same lender or a new federally regulated lender: no stress test. For refinances, equity take-outs, and any change that adds new money: qualifying rate is the greater of your contract rate + 2% or 5.25%. At today's market rates of ~4.29%, that's 6.29%. At 5.50% contract rate, it's 7.50%.
Can credit unions ignore the stress test? +
Yes — credit unions are provincially regulated and not bound by OSFI B-20 rules. Most of them voluntarily apply stress tests to manage risk, but they can use lower qualifying rates (contract rate + 1%, or even the contract rate itself) or waive the test entirely for existing members. This is a major reason credit unions are a strategic option when you fail the Big 6 stress test.
What happens if my GDS/TDS ratios exceed the OSFI limits? +
A federally regulated lender (Big 6 banks, most monolines) will decline the application. You have three options: reduce debts before reapplying, provide a larger down payment to lower the mortgage, or move to an alternative lender — a credit union, a B lender, or a MIC. B lenders charge 150–300 basis points more than A lenders and often require a 1–2% lender fee.
Related Guides
Stress Test Calculator
See if you qualify at today's benchmark qualifying rate.
Stress Test at Renewal
When the stress test applies, when it doesn't, and how to pass it.
OSFI B-20 Stress Test Rules
The federal qualifying rule and how it shapes renewal switches.
Rental Income Qualifying Calculator
How much of your rental income lenders will actually count.
Switching Lenders at Renewal
How to change lenders at renewal — no stress test on straight switches.
All Renewal Calculators
Payment, stress test, switch break-even, prepayment — all in one place.
Worried You Won't Qualify?
A licensed mortgage broker can test your file against every major Canadian lender's internal guidelines — free, with no credit pull until you're ready.