Mortgage affordability calculator
Income, debts, expenses, taxes, reserves, and rate stress to a prudent property range.
Enter income, debts, expenses, and reserves to see your total housing outflow, debt-service ratio, and a prudent property range — with the payment stressed at the offered rate plus 1, 2, and 3 points.
Key points
- Shows total housing outflow, debt-service ratio, and a prudent range.
- Stresses the payment at +1, +2, and +3 points.
- Flags if stressed housing costs exceed ~35% of net income.
- The lender’s maximum is not a household recommendation.
Inputs and outputs
Inputs: gross and net income, stable bonus, household size, other debt payments, loan amount, rate, term, tax, management/reserve/insurance/parking fees, maintenance reserve, retirement age, and expected income reduction.
Outputs: monthly payment, total housing outflow, total debt-service ratio, housing-to-net-income ratio, balance at retirement, total interest, and a minimum emergency fund.
How to interpret the result
A loan you can afford only at the initial rate is not affordable; the tool flags stressed costs above a prudent share of net income and a mortgage extending past your working income.
What the tool shows — and what it doesn’t
In short: Shows total housing outflow, debt-service ratio, and a prudent range; Stresses the payment at +1, +2, and +3 points; Flags if stressed housing costs exceed ~35% of net income; The lender’s maximum is not a household recommendation.
A calculator is only as good as its inputs and the scenarios you test, and it models arithmetic, not approval: it cannot tell you whether a lender will lend, what rate underwriting will actually offer, or how your circumstances will change. Use it to compare options and to stress-test — run a mortgage at the offered rate plus one, two, and three points, and a purchase at pessimistic as well as central assumptions — rather than to produce a single answer. Advertised rates are execution-month or example figures, not guaranteed offers, so treat any result as a planning estimate and confirm the real numbers with a dated written quotation before you commit.
Who this is for
- Buyers and borrowers modeling a decision
- Anyone stress-testing affordability
What this is not
- A guaranteed quote or approval
- A loan you can afford only at the initial rate is not affordable; the tool flags stressed costs above a prudent share of net income and a mortgage extending past your working income.
Frequently asked questions
Should I borrow the maximum approved?
Usually not; approval is an underwriting ceiling, not a household financial recommendation.
What is debt-to-income?
Annual scheduled debt repayments divided by qualifying annual income; it counts all your debts, not just the mortgage.