Mortgage & financing
Mortgage Affordability Calculator
Estimate a purchase budget from income, debt, housing-cost and down-payment assumptions.
Calculate your result
What this calculator estimates
Estimate a comfortable purchase budget. It combines the inputs below to produce Estimated purchase budget. Every assumption remains editable so the estimate can reflect the property, financing and location being evaluated.
Worked example
Using the displayed sample assumptions, the calculator produces $558,771. This is an illustration, not a market quote. Change one input at a time to understand what drives the result.
Inputs and assumptions
- Gross annual household income — sample input: 120000 currency units
- Monthly debt payments — optional — sample input: 600 currency units
- Maximum housing-cost ratio — sample input: 32 %
- Maximum total-debt ratio — sample input: 40 %
- Monthly property tax, heat and fees — sample input: 650 currency units
- Interest rate — sample input: 4.5 %
- Amortization — sample input: 25 years
- Available down payment — sample input: 100000 currency units
How to interpret the result
Compare the payment with your total housing budget, not income alone. Compare a conservative case with an expected case and keep a record of the assumptions used.
Common mistake to avoid
Avoid assuming the lowest advertised rate applies to every borrower. Local definitions, taxes, lending practices and measurement requirements can materially change the result.
Frequently asked questions
Is the maximum purchase price a lender approval?
No. It is a planning estimate based on the entered income, debts, rate and housing-cost assumptions.
Should I use the maximum result as my budget?
Consider maintaining room for repairs, utilities, insurance, closing costs and changes in income or interest rates.
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Reviewed 2026-09-08.