UK mortgage calculator
Work out your monthly payment, total interest, and total cost over the term — instantly. Repayment or interest-only, any deposit, any rate. UK figures, no sign-up.
UK · Free · No sign-up · No data shared
Mortgage Calculator
Monthly payment · Total interest · Total cost over the term
Monthly payment
£1,841
Repayment · 25y · 5%
Cost breakdown
Loan amount
£315,000
Loan-to-value (LTV)
90.0%
Total interest
£237,438
Total paid over term
£552,438
Indicative figures. Real mortgage offers vary by lender, credit profile, and product fees. Always confirm with an FCA-authorised mortgage broker before you commit.
How UK mortgages actually work
A UK mortgage is a loan secured against your property. You put down a deposit, the lender lends you the rest, and you pay it back in monthly instalments over a fixed term — usually 25 years, sometimes shorter or longer. The monthly payment depends on three things: the loan amount, the interest rate, and the term length.
Two thirds of UK mortgages are repayment mortgages. The monthly payment covers both the interest and a portion of the original loan, so by the end of the term the debt is fully cleared and you own the property outright.
Repayment vs interest-only
On a repayment mortgage, every payment chips away at the principal. Early on, most of the payment goes on interest; later, most of it goes on principal. By the final year, almost the whole payment is principal.
On an interest-only mortgage, every payment is pure interest. The principal stays the same. At the end of the term you still owe the original loan amount and must repay it in a single lump sum — typically from a maturing investment, savings, or by selling the property. Most residential interest-only mortgages today are restricted to buy-to-let or higher-net-worth lending.
Loan-to-value (LTV) and why it matters
LTV is the loan as a percentage of the property price. The better the LTV, the better the rates you can access. UK lenders price in tiers — typically 60%, 75%, 80%, 85%, 90%, and 95%. The biggest rate jumps usually fall at 85%, 90%, and 95%. A larger deposit pays back twice: smaller loan and better rate.
Fixed vs variable rates
A fixed-rate mortgage locks your rate for a set period — usually 2, 5, or 10 years. Your monthly payment is predictable but you pay an early repayment charge if you exit the deal early. A variable-rate mortgage moves with the Bank of England base rate or the lender’s standard variable rate. Cheaper when rates fall, more expensive when they rise.
How much you can borrow
Most UK lenders offer 4 to 4.5 times your gross annual income. A few specialist lenders go to 5 or 5.5 times for professionals or high earners. Joint applicants combine incomes. The exact figure depends on your credit profile, existing debts, deposit size, and the lender’s affordability stress test, which checks whether you could still afford the payments if rates rose by several percent.
Frequently asked questions
How is a UK mortgage payment calculated?
Repayment mortgage: M = P × r / (1 - (1+r)^-n) — where P is the loan, r is the monthly rate (annual ÷ 12), and n is total monthly payments (years × 12). Interest-only: monthly payment is simply P × r and the loan is still owed at the end.
What's the difference between repayment and interest-only?
On a repayment mortgage you pay back the loan plus interest every month, and own the property outright at the end. On interest-only, you only pay the interest — the full loan is still owed at the end and must be repaid in a lump sum.
How much deposit do I need?
Minimum 5% deposit at most lenders (95% LTV). 10% opens better rates, 15–25% gets you the most competitive deals. Above 95% LTV, rates and availability narrow sharply.
How much can I borrow?
Typically 4–4.5× your gross annual income, sometimes 5–5.5× for higher earners. Joint applicants combine incomes. Final figure depends on credit, existing debts, deposit, and the lender's affordability stress test.
What is loan-to-value (LTV)?
The loan as a percentage of the property price. £315,000 borrowed against a £350,000 property = 90% LTV. Lower LTV = better rates. Major rate jumps fall at 85%, 90%, and 95%.
Should I use a mortgage broker?
Most UK buyers do. Brokers access lender criteria and rates not always available direct, match you to lenders likely to approve you, and handle paperwork. Fee-free brokers are paid by the lender. Always confirm FCA-authorisation.
Is this calculator accurate?
It uses the standard UK amortising-loan formula and is accurate for monthly payments. It does not include product, valuation, or arrangement fees, which are typically added to the loan or paid upfront. For an exact figure including all fees, get a quote from an FCA-authorised broker.
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