UK Mortgage Repayment Calculator
Turn your estimated borrowing into a monthly mortgage payment and total interest cost.
Use calculator →
Borrowing estimate
Mortgage Affordability Calculator
Estimate how much mortgage you may be able to afford based on your household income, deposit, monthly commitments, interest rate and payment limit.
Search other calculators & tools
- ✓Income multiple vs monthly payment affordability
- ✓Includes deposit and monthly commitments
- ✓Shows the limiting factor behind your estimate
Calculate your estimated mortgage affordability
Enter your income, deposit and regular commitments. The calculator estimates borrowing using both an income multiple and a monthly payment cap.
How to use this calculator
- Enter your gross household income before tax.
- Add your available deposit and monthly financial commitments.
- Set the mortgage rate and term you want to test.
- Adjust the income multiple and payment share if you want a stricter or looser estimate.
Affordability formula
max_by_income_multiple = annual_income × income_multiple
max_monthly_payment =
(monthly_gross_income × payment_share)
- monthly_commitments
borrowing_by_payment =
present value of max_monthly_payment
over the chosen term and rate
estimated_max_borrowing =
lower of income multiple and payment affordability
The calculator uses the lower of the income-multiple estimate and the monthly-payment estimate. This keeps the result more cautious than using income alone.
Estimated max borrowing
£236,122.71
This is the lower of the income-multiple estimate and monthly payment estimate.
Estimated property budget
£266,122.71
This adds your deposit to the estimated maximum borrowing.
Max monthly payment used
£1,450.00
Based on your selected share of gross monthly income, minus monthly commitments.
Limiting factor
Monthly affordability
The monthly payment limit is lower than the income-multiple estimate.
4.5× income
35% payment share
This is an estimate only. Lenders can lend less or more depending on credit history, dependants, spending, property type, deposit size and their own affordability checks.
Ready to act on your result?
Once you have an estimated borrowing range, compare mortgage deals or speak to a broker to understand what lenders may actually offer.
Compare mortgage dealsCalculatorz may earn a commission if you use this link. This doesn't affect the result above.
What your affordability result means
Your estimated max borrowing is the calculator’s view of the mortgage amount that fits both your income multiple and your monthly payment limit. It is deliberately not shown as a guaranteed approval figure.
The property budget adds your deposit to the estimated borrowing amount. This gives a rough idea of the property price range you might look at before allowing for stamp duty, legal fees, surveys, moving costs and other buying costs.
The limiting factor explains what is holding the estimate down. If the result is limited by income multiple, your income cap is tighter. If it is limited by monthly affordability, the payment at the chosen rate and term is the tighter constraint.
Important: lenders do not use one universal formula. The final amount can change after a full affordability check, credit search and property assessment.
How mortgage affordability works
Mortgage affordability is the lender’s assessment of whether you can reasonably keep up with the mortgage payments. Income matters, but it is only one part of the decision.
A simple income multiple gives a quick starting point. For example, using 4.5 times household income on £60,000 gives a rough borrowing figure of £270,000. That does not mean a lender will automatically offer that amount.
Lenders also look at affordability from a monthly-payment angle. They consider existing debts, regular commitments, living costs, dependants and how the mortgage payment might change if rates rise.
Your deposit affects the property budget and loan-to-value. A larger deposit can reduce the lender’s risk and may open access to different mortgage deals, but it does not remove the need to prove the mortgage is affordable.
This calculator combines a simple income multiple with a monthly payment cap. The lower figure is used as the estimated max borrowing, which gives a more cautious result than using income alone.
What affects your mortgage affordability
- Household income: Higher reliable income usually supports more borrowing, but lenders still apply their own checks.
- Monthly commitments: Loans, credit cards, car finance and other regular payments can reduce affordability.
- Deposit size: A larger deposit increases your property budget and can improve loan-to-value.
- Mortgage rate: Higher rates mean the same loan costs more each month, which can reduce affordable borrowing.
- Mortgage term: A longer mortgage term can lower the monthly payment but may increase total interest over time.
- Credit profile: Missed payments, high credit use or limited credit history can affect lender decisions.
- Dependants and spending: Childcare, school fees and regular living costs can all affect affordability.
Mortgage affordability calculator FAQs
How much mortgage can I afford in the UK?
It depends on your income, deposit, monthly commitments, credit profile, mortgage rate and lender rules. This calculator gives an estimate by comparing income-based borrowing with payment-based affordability.
Do lenders use 4.5 times income?
Some lenders use income multiples around 4 to 4.5 times income as a broad starting point. Others may offer more or less depending on risk, income type, debts, deposit and affordability checks. A fixed-rate mortgage can give certainty on payments during the initial period.
Does a bigger deposit increase mortgage affordability?
A bigger deposit increases your overall buying budget and usually improves loan-to-value. It does not automatically increase the amount a lender believes you can afford each month.
Are credit cards and loans included in affordability?
Yes. Regular payments on loans, credit cards, car finance and similar commitments can reduce the monthly amount available for a mortgage payment.
Is this calculator a mortgage approval?
No. It is only an estimate. A lender or broker may issue an agreement in principle after assessing your income, spending, credit history, deposit and property details.
Should I borrow the maximum amount available?
Not always. Borrowing the maximum can leave less room for bills, repairs, rate rises and life changes. It is sensible to test a lower borrowing amount as well as the maximum estimate.
Key terms used in this calculator
These terms explain the main affordability and mortgage concepts behind the result.