UK Mortgage Calculator
Estimate UK repayment or interest-only mortgage costs and how much lenders may offer.
About the UK Mortgage Calculator
Enter the property price, your deposit, the interest rate and term, and choose repayment or interest-only. Add your household income to see the typical range lenders offer. The calculator gives the monthly payment, the loan-to-value and the total interest.
Most UK mortgages are fixed for 2–5 years, then move to the lender's standard variable rate unless you remortgage. Lenders typically offer 4–4.5 times household income, subject to affordability checks and stress testing. Stamp Duty Land Tax is extra.
The formula
Repayment = P × i ÷ (1 − (1 + i)⁻ⁿ); interest-only = P × rate ÷ 12
Worked example
£300,000 home, £30,000 deposit, 4.5% over 25 years
- Borrowing £270,000 at 90% LTV
- Repayment mortgage: £1,500.75 a month, £180,224 of interest
- Interest-only: £1,012.50 a month, but the full £270,000 is still owed at the end
Things to keep in mind
- Uses one rate for the whole term; after a fixed deal ends the rate usually changes.
- Arrangement fees, stamp duty and insurance aren't included.
Questions people ask
What deposit do I need?
Usually at least 5%; 10–25% gets better rates.
Should I fix?
Fixing gives certainty; check early repayment charges.
How much could I borrow on £70,000?
Typically £280,000–£315,000 (4–4.5×), depending on outgoings and the lender.