GDSR / TDSR calculator
The two ratios that decide whether a lender says yes: GDSR (housing) and TDSR (housing + other debt). Compute them in 30 seconds, no credit score, no SIN. You will know if you are in the green zone (A bank), yellow (edge) or red (B lender / monoline).
Estimates are OK for taxes and heating. We use Canadian standard thresholds (A banks) — an AMF-licensed mortgage broker from the Courteo network will then look at the actual lender grid.
Total: credit card minimums + car loan + lines of credit + student loans + alimony.
Monthly housing cost
$2,600
Mortgage PMT + taxes + heating + 50% condo.
| Ratio | You | Standard thresholds | Zone |
|---|---|---|---|
| GDSR (housing only) | 32.8 % | Green ≤ 35.0 % · Yellow 35.0 %–39.0 % · Red > 39.0 % | Green |
| TDSR (housing + other debt) | 38.5 % | Green ≤ 42.0 % · Yellow 42.0 %–44.0 % · Red > 44.0 % | Green |
Green zone — you pass A bank qualification
Your ratios sit below the standard thresholds of major lenders. You can shop for the lowest rate accessible for your profile — an AMF-licensed mortgage broker from the Courteo network sees 20+ lenders in a single mandate.
These ratios are a signal, not a credit decision. A lender may accept or decline a profile outside the standard zones.
A lender first looks at your ability to pay, not your net worth. The two standard ratios used by every Canadian bank to check that: GDSR (Gross Debt Service Ratio) for housing cost alone, and TDSR (Total Debt Service Ratio) which adds all your other debt. Credit score, employment history, income stability — all of that comes next as modulators.
If both ratios sit below the standard thresholds, your file goes almost automatically to an A bank at the lowest rate accessible for your profile. If one exceeds, the lender’s underwriter looks at everything else — and that is where a well-presented file from an AMF-licensed broker makes a difference.
Total housing cost over 12 months divided by your gross annual income. Housing cost includes: mortgage monthly payment (principal + interest), property taxes, heating, and 50% of condo fees if applicable (CMHC rule). Standard A bank threshold: ≤ 35% green zone, 35-39% yellow, > 39% red.
GDSR plus all other monthly debt annualized: credit card minimums, car loan, lines of credit, student loans, alimony. Standard A bank threshold: ≤ 42% green zone, 42-44% yellow, > 44% red. This is often where files break — lines and cards weigh more than people think.
GDSR ≤ 35% and TDSR ≤ 42%
You pass qualification at most A banks without friction. At this stage, the question is no longer "will I qualify" but "which lender gives me the lowest rate accessible for my profile". Shopping via an AMF-licensed mortgage broker from the Courteo network accesses 20+ lenders in a single mandate — without running 20 interviews.
GDSR 35-39% or TDSR 42-44%
You are at the edge. A bank may say yes or no depending on its internal grid (credit score, file structure, lender). Three things move the outcome: credit score (above 720 helps), employment stability (2+ years same employer is solid), and the chosen lender (some A lenders accept up to 39/44 without penalty, others do not). An AMF-licensed mortgage broker knows which.
GDSR > 39% or TDSR > 44%
A banks will very likely decline. Two paths remain: (1) reduce the ratio — pay a debt, extend amortization to 30 years, raise the down payment — to drop back to yellow; (2) accept going to a B lender (Equitable Bank, Home Trust, B2B Bank) or an alternative monoline (MCAP, First National, etc.) that accept ratios up to about 44/50 depending on program, with a typical rate spread of 25-75 basis points. An AMF-licensed broker presents both options.
First instinct: do not panic and do not stack loan applications. Each cascading credit pull damages your score — and the score matters more when you are in the red.
Second instinct: an AMF-licensed mortgage broker from the Courteo network reviews your actual file (income, debts, score, history), picks the lender BEFORE submitting, and presents the file in the right format. A B lender’s underwriter spends 15 minutes on your file, not 2 — presentation quality makes a real difference.
Third instinct: if you are self-employed, admissible income is not computed the same way as for a T4 employee. Many self-employed files that look red on the generic grid land yellow or green with a lender that has a self-employed program.
Public methodology details: /methodologie.