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Mortgage Affordability Calculator

Estimate how much house you can afford based on income, debts, down payment, and interest rate.

Tested tool guide Tested browser tools Checked August 16, 2026

What Mortgage Affordability Calculator does and how it behaves

Mortgage affordability has two linked limits: the payment supported by the entered income and debts, and the purchase price completed by the available down payment. This calculator combines those figures with the interest rate to estimate how much house the scenario can support. More recurring debt leaves less room for a mortgage payment, while a larger down payment reduces the amount that must be financed. The result users most often misread is the estimated home price. It is a planning figure, not a loan approval or a complete estimate of the cash required to close.

How the result is produced

1

Income and debt capacity

Entered income establishes the household resources available for housing, while recurring debt payments consume part of that capacity before a mortgage is added. The calculator combines those values to determine the mortgage payment the inputs can support. It then connects that payment capacity to a home-price estimate. Treat the displayed limit as the calculator's scenario result, not as a universal borrowing maximum.

2

Down payment and rate

The down payment is the portion of the price paid without mortgage borrowing, so it increases the total price reachable from a given loan amount. The interest rate works in the opposite direction: for the same principal and mortgage term, a higher rate produces a higher principal-and-interest payment. The calculator uses these relationships to translate payment capacity into a financed amount and corresponding purchase price.

Good uses

  • Set an initial listing-price ceiling before contacting an agent by entering current household income, recurring debt payments, available down payment, and a plausible mortgage rate.
  • Compare two down-payment plans to see how retaining more savings or putting more cash into the purchase changes the estimated affordable price.
  • Test several interest-rate scenarios during a home search to see how rate changes could narrow or expand the price range supported by the same finances.

Limits and checks

  • Enter income in the period and form requested by the field labels. Confusing annual with monthly income can change the input by a factor of 12, while confusing gross income with take-home pay mixes different budget measures.
  • Confirm whether property taxes, homeowners insurance, association dues, and mortgage insurance are represented. Any costs not included in the calculation still affect the real monthly housing bill and may reduce a lender's permitted loan amount.
  • Do not treat every available dollar as down payment automatically. Closing expenses, prepaid taxes or insurance, moving costs, repairs, and required reserves can consume cash separately from the amount applied to the purchase price.

Common questions

Why does a larger down payment increase the affordable home price?

It pays for more of the purchase without increasing the mortgage principal. If the payment-supported loan amount remains unchanged, adding $10,000 to the down payment raises the reachable purchase price by $10,000. The change may differ if other modeled costs respond to the loan-to-value ratio, so compare the displayed scenarios rather than assuming an additional effect.

Will a lender approve the amount shown by this calculator?

No, not necessarily. The result summarizes the entered affordability scenario. A lender may also examine documented income, credit history, existing obligations, property-related costs, loan type, cash reserves, and its own underwriting requirements. Use the estimate to choose a search range, then obtain lender-specific figures before relying on it for an offer.

References and verification

The behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.

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