FinToolSuite

Home Affordability Calculator

Updated April 17, 2026 · Mortgage · Educational use only ·

What home can you actually afford?

Calculate maximum home price you can afford based on income and debts. Enter gross income and available deposit for an instant result.

What this tool does

This tool calculates maximum home price based on monthly income, deposit, mortgage rate, term, and existing debts.


Enter Values

Formula Used
Max loan at 28% DTI
Deposit

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Disclaimer

Results are estimates for educational purposes only. They do not constitute financial advice. Consult a qualified professional before making financial decisions.

Home affordability depends on income, deposit, mortgage rate, and existing debts. Lenders typically cap mortgage payments at 28% of gross income. This calculator shows maximum home price you can afford.

5,000 monthly income × 28% = 1,400 max payment. After 300 monthly debt, 1,100 remaining. At 4.5% 30-year rate, that supports 217k loan. Plus 40k deposit = 257k max home price.

Use as starting point. Lenders vary - some allow 35-40% ratio on high credit/low debt. Different countries use different ratios. Actual approval depends on credit score, employment stability, and lender criteria.

A worked example

Try the defaults: monthly gross income of 5,000, available deposit of 40,000, mortgage rate of 4.5%, mortgage term of 30. The tool returns 257,097.27. You can adjust any input and the result updates as you type — no submit button, no reload. That's the real power here: seeing how sensitive the output is to one or two assumptions.

What moves the number most

The result responds to Monthly Gross Income, Available Deposit, Mortgage Rate, Mortgage Term, and Monthly Debt Payments. Not every input has equal weight. Flip one at a time toward extreme values to feel which ones move the needle most for your situation.

The formula behind this

Max monthly = income × 28%. Net payment available = max - existing debts. Max loan = amortisation with net payment at rate and term. Max home = loan + deposit. Everything the calculator does is shown in the formula box below, so you can check the math against your own spreadsheet if you want.

Why this matters before you sign

A mortgage is usually the biggest single financial commitment a person makes. The difference between a well-chosen product and a hasty one can run into tens of thousands over the life of the loan. Running the numbers here before committing is the cheapest form of due diligence available.

What this doesn't capture

The figure excludes arrangement fees, valuation costs, legal fees, insurance, and any early-repayment charges — those can add several thousand to the headline cost. Rate changes at renewal for fixed-term deals will shift the picture further. Use this for the core interest/principal math and add the other costs on top.

Example Scenario

£5,000 £/mo income + £40,000 £ deposit at 4.5% × 30 yearsyrs - £300 £ debts = $257,097.27.

Inputs

Monthly Gross Income:5,000 £
Available Deposit:40,000 £
Mortgage Rate:4.5
Mortgage Term:30 years
Monthly Debt Payments:300 £
Expected Result$257,097.27

This example uses typical values for illustration. Adjust the inputs above to match a specific situation and see how the result changes.

Sources & Methodology

Methodology

Max monthly = income × 28%. Net payment available = max - existing debts. Max loan = amortisation with net payment at rate and term. Max home = loan + deposit.

Frequently Asked Questions

Is 28% the right ratio?
Traditional mortgage affordability cap. Some lenders use 33-35% for low-risk borrowers. More conservative planners use 25%. 28% is good default for safe affordability.

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