GDS and TDS calculator at the qualifying rate
Lenders divide your housing costs at the qualifying rate (mortgage, property tax, heating, half of condo fees) by gross monthly income. That's GDS, capped at 39% for insured loans. Add your other debt payments and you get TDS, capped at 44%. This tool shows every line, at both rates.
GDS and TDS at the qualifying rate
Line by line, the way a lender adds up your ratios for one price.
| Line | At 6.12% | At 4.12% |
|---|---|---|
| Mortgage payment (incl. premium) | $3,360 | $2,691 |
| Property tax | $400 | $400 |
| Heating | $100 | $100 |
| Condo fees (50%) | $0 | $0 |
| GDS costs | $3,860 | $3,191 |
| Car and other loans | $450 | $450 |
| Student loans | $0 | $0 |
| Cards and lines of credit (3% of balance) | $75 | $75 |
| TDS costs | $4,385 | $3,716 |
| GDS ratio | 42.1% | 34.8% |
| TDS ratio | 47.8% | 40.5% |
Estimate, not advice. Educational estimate only, not financial, mortgage, tax or legal advice. Lenders, insurers and governments set their own rules and can change them; confirm with a licensed professional before you decide.
GDS 42.1%, TDS 47.8% at 6.12%. Does not pass.
Assumptions & sources
Assumptions
- GDS and TDS limits: CMHC's 39% and 44% for insured loans. Uninsured lenders set their own, often similar.
- Revolving balances (cards, lines of credit) are counted at 3% of the balance per month, a common lender convention; a secured line of credit may instead be counted at its own payment.
- Insurance premium is added to the mortgage when the down payment is under 20%.
Sources
- CMHC — Calculating GDS / TDS. Checked .
- OSFI — Minimum qualifying rate for uninsured mortgages (effective January 29, 2026). Checked .
- CMHC — Homeowner mortgage loan insurance: Purchase (eligibility). Checked .
| Household income | $98,000 |
|---|---|
| Price and down payment | $520,000, $52,000 down |
| Property tax, heating, condo fees | $4,100/yr, $110/mo, $380/mo |
| Car loan, student loan | $420 and $150 a month |
| Credit card balance | $6,000Counted at 3% = $180 a month |
| Qualifying rate | 6.12% |
| Mortgage incl. premium | $482,508 |
| GDS costs a month | $3,763Payment at 6.12% + tax + heat + half the condo fees |
| GDS | 46.1% (limit 39%) |
| TDS | 55.3% (limit 44%): fails |
Both ratios are shown line by line; the tool lets you change any line and watch which limit moves.
Open this example in the calculator →Computed November 1, 2026.
How this calculator works
For one purchase price, the tool builds the lender's worksheet: the mortgage payment at the qualifying rate (with the insurance premium added to the loan if you put down less than 20%), monthly property tax, heating and 50% of condo fees. That total over gross monthly income is GDS. Your other debt payments are added for TDS.
Credit cards and lines of credit are counted at 3% of the balance each month even if you pay less, which is why a large card balance can sink TDS. The right-hand column shows the same worksheet at your contract rate, so you can see exactly how much of any shortfall is the stress test.
Frequently asked questions
What are the maximum GDS and TDS ratios in Canada?
For insured mortgages CMHC's limits are 39% GDS and 44% TDS, with a minimum credit score of 600 for at least one borrower. Uninsured lenders set their own limits; many use similar figures.
Are GDS and TDS calculated at my actual rate?
No. Federally regulated lenders and every insured mortgage use the qualifying rate (your rate + 2 points or 5.25%, whichever is higher) for the mortgage payment in both ratios.
How are credit card balances counted?
Lenders commonly count 3% of the outstanding balance as the monthly payment, whatever you actually pay. Paying a card down before you apply lowers TDS directly.
Primary sources
- CMHC — Calculating GDS / TDS. Checked .
- OSFI — Minimum qualifying rate for uninsured mortgages (effective January 29, 2026). Checked .
- CMHC — Homeowner mortgage loan insurance: Purchase (eligibility). Checked .