MortgageAffordabilityTools

Mortgage Affordability Calculator

Find the home price your income, debts and deposit support at a given debt-to-income limit.

Last reviewed

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Free · No sign-up · Runs in your browser

Affordability is decided by a ratio, not by a feeling. Lenders cap total monthly debt at a percentage of gross income, and everything else - the price, the loan, the deposit - falls out of that constraint once the other costs are known.

This calculator solves for the price at which total monthly debt reaches the limit you set. It includes property tax and insurance in the calculation, because lenders do, and because leaving them out overstates the answer by a wide margin.

Your numbers

Results update as you type. Nothing is sent anywhere.

Result

Maximum home price

$461,479

Maximum housing payment

$3,100

Maximum loan
$421,479
Principal and interest
$2,527
Property tax
$423
Insurance
$150
Gross monthly income
$10,000
Housing ratio
31%
Total debt ratio
36%

The price shown is the point where total monthly debt reaches the debt-to-income limit you entered. Lenders also review credit history, reserves, employment and property type.

Property tax is estimated from the tax rate you entered applied to the purchase price, not to an assessed value.

How to use the mortgage affordability calculator

  1. Enter gross annual income and total monthly payments on existing debts.
  2. Enter the deposit you have available and the rate and term you expect.
  3. Enter the local property tax rate, annual insurance and any HOA dues.
  4. Set the debt-to-income limit and read the maximum price.

What people use this for

  • Setting a realistic price range before viewing properties.
  • Seeing how much clearing a debt increases buying power.
  • Testing the effect of a larger deposit on the achievable price.
  • Checking whether a property you like is within reach.

Worked examples

Every figure below is produced by running this calculator against the example inputs, so the numbers always match the tool.

A household with modest debts

$120,000 income, $500 of monthly debts, $40,000 deposit, 6% over 30 years, 1.1% tax, $1,800 insurance, 36% limit.

Maximum home price
$461,479
Maximum housing payment
$3,100
Total debt ratio
36%

The same household after clearing a car loan

Identical figures with monthly debts reduced to zero.

Maximum home price
$533,815
Maximum loan
$493,815
Principal and interest
$2,961

Existing debts cost more than they look

At a 36% limit, every dollar of existing monthly debt removes a dollar from the housing payment - and a dollar of housing payment supports roughly $150 to $170 of purchase price at typical rates. A $400 car payment is therefore worth around $60,000 of house.

That is why clearing a car loan or a credit card frequently does more for buying power than saving another few thousand of deposit, and it is worth testing both before deciding where to put spare cash.

What the ratio does not capture

A lender applies the ratio and then looks at everything else: credit history, employment stability, reserves after closing, the property itself, and how the loan programme treats each of them. The ratio is a gate, not an approval.

It also says nothing about whether the payment is comfortable. A household at exactly the limit has no margin for a rate reset, a repair, or a change in income, and lenders do not price that risk on your behalf.

Methodology and assumptions

What this calculator does, and what it deliberately does not do.

  • The maximum housing payment is the DTI limit applied to gross monthly income, less existing monthly debts.
  • The price is solved so that principal, interest and property tax together consume the payment remaining after insurance and HOA.
  • Property tax is estimated from the rate applied to the purchase price rather than to an assessed value.
  • Results are estimates. Real quotes depend on credit, income, property, loan programme and lender pricing at the time of application.
  • Nothing you type is transmitted or stored - the calculation runs entirely inside your browser.

This calculator is provided for informational and educational purposes only. Results are estimates and may not reflect actual rates, fees, taxes, or market conditions.

This website is not a lender, a mortgage broker or a financial adviser. It does not originate loans, does not accept applications and does not forward your details to anyone.

Actual loan terms depend on credit history, income, the property, the loan programme and lender pricing at the time of application. Only a lender can tell you what you qualify for.

Frequently asked questions

What debt-to-income limit should I use?

Limits differ by loan programme and by lender, and a strong file can frequently exceed the standard figure. Use what your lender tells you rather than the default.

Is gross or net income used?

Lenders use gross income before tax. That is what the calculator expects, and it is also why the resulting payment can feel larger than it looks on paper.

Does this include mortgage insurance?

No. If the deposit is below 20%, add the annual PMI cost to the insurance field for a closer estimate.

Should I borrow the maximum?

Rarely. The maximum is where a lender stops, not where comfort ends. A payment set below it leaves margin for the costs that follow a purchase.

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