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GDS and TDS ratio calculator

GDS is your housing costs (mortgage payment at the qualifying rate, property tax, heating and half of condo fees) divided by gross monthly income; TDS adds your other debt payments. CMHC, Sagen and Canada Guaranty cap them at 39% and 44% for insured mortgages.

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GDS and TDS ratio calculator

Check a specific home against CMHC's 39% / 44% limits at the qualifying rate.

Amortization
50% is counted.
Above CMHC's limits40.9% / 47.4%GDS / TDS at the qualifying rate
GDS40.9% of 39% limit
TDS47.4% of 44% limit
Qualifying P&I payment
$3,302
at 6.12%
Property tax + heat + ½ condo
$444
Room left under GDS
-$170
per month
Room left under TDS
-$312
per month
What would fix itLower the price, add to the down payment, pay off a monthly debt (each $100/month of debt removed adds $100 of TDS room), or add a co-borrower's income.

GDS 40.9 percent, TDS 47.4 percent. Above the limits.

Assumptions & sources

Assumptions

  • GDS = (P&I at the qualifying rate + property tax + heating + 50% of condo fees) ÷ gross monthly income. TDS adds other monthly debt payments.
  • Limits: 39% GDS and 44% TDS (CMHC; Sagen and Canada Guaranty publish the same). Uninsured lenders set their own.
  • If the down payment is under 20%, the CMHC premium is added to the mortgage before the payment is calculated.

Sources

  1. CMHC — Calculating GDS / TDS. Checked .
  2. Canada Guaranty — Products at a glance (effective July 1, 2025). Checked .
  3. OSFI — Minimum qualifying rate for uninsured mortgages (Guideline B-20). Checked .
  4. CMHC — Mortgage loan insurance cost (premium table). Checked .

How this calculator works

Enter the home you're looking at. The calculator adds a CMHC premium if you have less than 20% down, works out the principal-and-interest payment at the qualifying rate, then divides your monthly housing costs (and debts) by gross monthly income.

"Room left" tells you how much more monthly cost each ratio could take. Negative means you're over the limit. Learn more in GDS and TDS explained.

Frequently asked questions

What is a good GDS and TDS ratio?

For an insured mortgage the maximums are 39% GDS and 44% TDS. Lower is more comfortable; many households aim for housing costs nearer 30–35% of gross income.

Are condo fees included in GDS?

Yes: 50% of monthly condo fees count in both GDS and TDS under CMHC's method.

Is the GDS ratio calculated at my rate or the stress-test rate?

At the qualifying (stress-test) rate, the greater of your rate plus 2 points or 5.25%.

What debts count in TDS?

Every monthly debt payment: car loans and leases, student loans, lines of credit, credit-card minimum payments and support payments, plus your housing costs.

Primary sources

  1. CMHC — Calculating GDS / TDS. Checked .
  2. Canada Guaranty — Products at a glance (effective July 1, 2025). Checked .
  3. OSFI — Minimum qualifying rate for uninsured mortgages (Guideline B-20). Checked .
  4. CMHC — Mortgage loan insurance cost (premium table). Checked .
GDS and TDS explainedWhat counts and how to lower each ratio.Open →Income needed calculatorThe income this home would take.Open →Ways to afford moreWhich changes move your ratios most.Open →