Mortgage calculator
Mortgage Qualification Calculator
This calculator compares a proposed home purchase with the qualification limits used in this calculation. It estimates GDS and TDS from the mortgage, housing costs, gross household income and other debt payments you enter. It is an educational comparison, not lender approval.
Thinking about a home purchase?
Use the Home Purchase Affordability Guided Route to place price, down payment, borrowing, monthly pressure, and ownership costs in context before preparing an educational briefing.
The guided route is being reviewed publicly. It uses blank fields with example placeholders, so the briefing is based on the amounts entered during the route.
How this estimate works
The calculator determines the mortgage amount and, when applicable, adds the estimated financeable mortgage-insurance premium. It then calculates the payment used for qualification, compares housing costs with gross household income for GDS, and adds other debt payments for TDS. The result shows whether the proposed purchase is within or above the qualification limits used in the calculation.
Key calculation assumptions
The calculation uses the entered mortgage contract rate together with the qualifying-rate assumptions shown in the calculator. Income and property taxes are annual inputs; heating, condominium fees and other debt payments are monthly. The debt-service calculation uses 50% of condominium fees. The calculator does not use a personal “comfortable payment” amount when determining GDS or TDS.
Supported scope
This calculator is designed for owner-occupied purchases with one or two residential units and a non-borrowed down payment. It supports the insured and uninsured purchase scenarios described in the Mortgage Qualification Rules reference. It does not estimate the household’s maximum purchase price; that is the purpose of the Home Affordability Calculator.
Detailed rules
For the qualifying-rate test, GDS and TDS definitions, minimum down-payment rules, mortgage-insurance premiums, longer insured amortizations and full worked examples, see the Mortgage Qualification Rules reference.
Example
Suppose a proposed home purchase has a price of $800,000, a $200,000 down payment, a 5.00% mortgage contract rate and a 25-year amortization. The household has gross annual income of $180,000, annual property taxes of $6,000, monthly heating costs of $150, monthly condominium fees of $400 and $800 of other monthly debt payments.
The base mortgage is $600,000. At the 7.00% qualifying rate used in this example, the mortgage payment for qualification is approximately $4,202.49 per month. GDS is approximately 33.68% compared with a 39.00% limit, and TDS is approximately 39.02% compared with a 44.00% limit. The proposed purchase is therefore within both debt-service limits used in this example.
Limitations
This calculator does not reproduce a lender’s complete underwriting process. It does not assess creditworthiness, verify income or debts, determine mortgage-insurance or property eligibility, or provide mortgage approval. Lenders and insurers may apply different requirements, and the rules and source information used by the calculator can change. The result is an educational comparison and may contain errors or omissions.
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Related References
The shared reference explains the stress test, GDS/TDS, minimum down payments, insurance premiums, longer amortizations and the complete calculation examples.