Find out how much house you can afford based on your income, debts, deposit and interest rate.
Rates as of Q2 2025 (example)
A house affordability calculator estimates the maximum property price you could afford based on your income, existing monthly debts, deposit, and the costs of homeownership — including council tax, buildings insurance, and any service charge. It works backward from a target debt-to-income ratio to figure out how much mortgage you could comfortably take on, and adds your deposit to estimate a maximum property price.
The calculator first works out your maximum total monthly debt payment based on your income and target debt-to-income ratio, then subtracts your existing debts to find your remaining housing budget. It subtracts council tax, buildings insurance, and service charge (which don't go toward the mortgage) to find what's left for principal & interest, then works backward through the mortgage formula — combined with your deposit — to estimate a maximum property price.
Formula: Max Total Debt Payment = Monthly Income × DTI Ratio. Max Housing Budget = Max Total Debt Payment − Existing Monthly Debts. Max Principal & Interest = Max Housing Budget − (Council Tax + Insurance + Service Charge, monthly). Loan Amount = Max Principal & Interest ÷ Mortgage Payment Factor. Property Price = Loan Amount + Deposit.
Example: With a £45,000 annual income (£3,750/month), a 36% debt-to-income ratio (example ratio), and £300 in existing monthly debts, the maximum total debt payment is £1,350, leaving £1,050 for housing costs. After subtracting roughly £163/month for council tax and buildings insurance, about £887 is available for principal & interest. At a 5.25% interest rate (example rate — enter your actual rate) over 25 years, this supports a loan of roughly £148,000 — combined with a £30,000 deposit, that's a maximum property price of around £178,000. (Note: all figures in this example are for illustration purposes only and do not represent a mortgage offer.)
UK mortgage lenders typically assess affordability using their own criteria, often based on income multiples (commonly around 4 to 4.5 times annual income, sometimes more for higher earners or with certain lenders) combined with detailed affordability checks that consider your actual income, outgoings, dependants, and existing debts — and they "stress test" your ability to repay at a higher interest rate than you'd actually pay, in case rates rise. The debt-to-income approach used by this calculator is a useful estimate for your own budgeting, but the actual amount a lender will offer depends on their specific criteria, which can vary significantly between lenders. Council tax bands and rates vary by local authority and property value, so use an estimate appropriate for the area and property type you're considering.
UK lenders commonly use income multiples of around 4 to 4.5 times your annual income as a starting point, though this varies by lender and depends on a full affordability assessment of your income, outgoings, and existing debts. This calculator uses a debt-to-income approach as an estimate — get a mortgage in principle from a lender for an accurate figure.
Debt-to-income (DTI) ratio is the percentage of your gross monthly income that goes toward debt payments, including your mortgage. A lower DTI ratio generally means more affordable, conservative borrowing, while a higher DTI ratio means a larger share of your income is committed to debt payments.
No. This calculator estimates the property price you can afford based on ongoing monthly costs (mortgage payment, council tax, insurance, service charge). Upfront costs like Stamp Duty Land Tax, solicitor fees, surveys, and moving costs are separate and should be budgeted for in addition to your deposit.
Your deposit reduces the loan amount needed, which reduces the monthly principal & interest payment for a given property price — effectively "freeing up" more of your monthly budget, which the calculator converts back into additional borrowing capacity. So a larger deposit increases the affordable property price by more than just the deposit amount itself.
No — the default is an example only. Mortgage rates vary by lender, product, fixed-rate period, and your loan-to-value ratio. Use a realistic current rate for your circumstances, and remember lenders also stress-test affordability at higher rates than you'd actually pay.
Council tax is a significant recurring cost that reduces the amount of your monthly budget available for mortgage payments. Council tax bands and amounts vary by local authority and property valuation band, so use a realistic estimate for the area and property type you're considering.
Disclaimer: The information, rates, and figures provided on this page are for educational and illustrative purposes only and do not constitute a mortgage offer, pre-approval, or financial advice. Actual lending amounts depend on individual lender criteria, affordability assessments, and credit checks. The default interest rate and debt-to-income ratio are sample values. Always consult a mortgage lender or broker and a qualified financial adviser before making any property purchase decisions.