Reviewed by Scott Dillingham · Licensed Mortgage Agent (Ontario, Level 2) · Updated September 1, 2026
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
Full prescribed MQR math — refinance, new money, or amortization change. Not a silent skip for switches.
6.29%
Contract + 2% — refi / new money
35.98%
Within limit
41.55%
Within limit
YES
Full MQR — not a switch model
$593,476
Qualifying at 6.29%
$719,745
What payment actually buys at 4.29%
You qualify up to $593,476 under the stress test. A broker can find lenders with best ratio flexibility.
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What these numbers mean.
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 ~4.09% (insured) to ~4.24% (uninsured), the qualifying rate is 6.09–6.24%. 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 21, 2024 OSFI update exempted uninsured straight-switch renewals from the prescribed MQR. If you're moving from one federally regulated lender to another at renewal, with the same balance and same or shorter amortization, the prescribed MQR does not apply — B-20 overlays can still apply.
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 Prescribed MQR Typically Is Not Re-Applied
- Uninsured straight-switch renewal — same balance, same or shorter amortization, no new money (exempt from prescribed MQR since Nov 21, 2024; B-20 overlays remain)
- Insured-to-insured transfers — mortgage insurance usually travels with the borrower; prescribed MQR typically not re-applied on a straight transfer, but the new lender can still apply overlays
- Credit union renewals / new mortgages — provincially regulated credit unions are not bound by OSFI B-20 and set their own qualifying tests
- Private / MIC — not OSFI-bound; they 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
Does this calculator skip the stress test if I switch lenders?
No. This tool always applies the full prescribed MQR (greater of contract rate + 2% or 5.25%). Prescribed MQR applies to new money, refinance, and amortization changes. An uninsured straight switch (same balance, same or shorter amortization) is exempt from the prescribed MQR, but Guideline B-20 and lender overlays can still apply.
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 exempts uninsured straight-switch renewals from the prescribed MQR — same balance, same or shorter amortization, no new money. Overlays can still apply. If you're taking cash out, extending amortization, or adding a borrower, you must qualify at the MQR (greater of contract + 2% or 5.25%).
What qualifying rate applies to renewals in 2026?
For a same-lender simple renewal, the prescribed MQR is typically not re-applied. For an uninsured straight switch to a new federally regulated lender: prescribed-MQR exempt since November 21, 2024; overlays remain. 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 September 2026 snapshot rates of ~4.09% insured / ~4.24% uninsured, that's 6.09–6.24%.
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 — prescribed-MQR exempt on uninsured straight switches; overlays remain.
All Renewal Calculators
Payment, stress test, switch break-even, prepayment — all in one place.
The numbers check out — now what?
Book a call for live offers, or check today's best renewal rates.