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CalcTortoise

Home Affordability Calculator

Enter your income, existing repayments and savings to see the most you can spend on a home, and which limit — income or deposit — holds you back.

Written by the CalcTortoise editorial team · How we work

years
Assumed: 40% of income for loan payments, 5% taxes and fees on buying, 80% largest loan. Change

Lenders set their own limit; 35–45% is common.

Affordable price at other rates

Interest rateHome priceLoan amountMonthly loan payment
At 2%$240,000$192,000$814
At 3%$240,000$192,000$910
At 4%$240,000$192,000$1,013
At 5%$240,000$192,000$1,122
At 6%$240,000$192,000$1,237
At 7%$240,000$192,000$1,357
At 8%$240,000$192,000$1,482

How to use this calculator

  1. Enter your monthly income after tax and your other loan repayments.
  2. Set the lender’s limit, the interest rate and the term.
  3. Enter your savings, the largest loan-to-value the lender offers and the buying costs.

Frequently asked questions

How much can I borrow for a home?

Lenders cap the share of your income that loan repayments may take. With $6,000 a month after tax, $300 already going to other loans and a 40% limit, $2,100 a month is left for the mortgage — enough to borrow about $359,226 at 5% over 25 years.

Which limit matters more, income or deposit?

Whichever is lower. In the example the deposit is the constraint: your income alone would support $399,262, and your savings alone $240,000.

How sensitive is this to the interest rate?

Very. At 6% instead of 5%, the affordable price falls from $240,000 to $240,000.

What are buying costs?

Property transfer taxes, stamp duty, legal and registration fees. They are paid from your own savings, so they reduce the deposit you can put down.

Sources and method

Standard compound-interest formulas, tested against worked examples. Nothing here depends on outside data; the rates you type in are your own assumptions.

No outside data is used. The numbers you type in are the only inputs.

Page and formula last reviewed . How we calculate · Editorial policy · Corrections and change log

Last updated 10 October 2026. For information only — not financial advice. Check the final figures with your lender or bank.