UK Mortgage Calculator

Estimate monthly mortgage payments in the UK, compare repayment vs interest-only, and review deposit, loan amount, LTV, total interest, and total paid.

How to Use

  1. Enter the property price.
  2. Choose whether to enter the deposit in pounds or as a percentage.
  3. Set the interest rate, mortgage term, and mortgage type.
  4. Add an optional monthly overpayment to see the effect on cost and term.
  5. Review the monthly payment, mortgage amount, LTV, total interest, and Show Work panel.
Mortgage Snapshot

Live UK Estimate

Designed for fast what-if testing with clear totals and cost breakdowns.

Monthly Payment
—
Mortgage Amount
—
Deposit
—
LTV
—
Loan-to-Value —

Enter property price and deposit to calculate LTV.

Total Interest —
Total Paid —
Optional Overpayment —
Estimated Payoff —
Inputs & Settings
All values are estimates for planning only and do not include lender-specific fees or underwriting decisions.
Total purchase price of the home.
Choose how you want to enter the deposit.
Used when deposit mode is set to pounds.
Used when deposit mode is set to percentage.
Nominal annual rate used for the estimate.
Typical UK terms range from 10 to 40 years.
Repayment reduces the balance over time; interest-only does not.
Optional. Used to estimate faster payoff and lower interest.
£325,000
4.85%
25 years
Show Work (step-by-step)
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Work is shown using standard monthly mortgage formulas. Figures are estimates and may differ from actual lender offers.

Formula & Details

Repayment mortgage: monthly payments cover both interest and principal, so the balance reduces over time.

Interest-only mortgage: monthly payments cover interest only, so the original mortgage balance remains unless repaid separately.

  • Mortgage amount: Property Price − Deposit
  • LTV: Mortgage Amount ÷ Property Price × 100
  • Monthly rate: Annual Rate ÷ 12
  • Repayment payment: standard amortisation formula
  • Interest-only payment: Mortgage Amount × Monthly Rate

This tool is for planning and comparison. It does not include arrangement fees, valuation fees, solicitor costs, insurance, or stamp duty.

FAQ

What is LTV?

LTV means loan-to-value. A lower LTV usually means less risk to the lender and may unlock better mortgage rates.

What is the difference between repayment and interest-only?

Repayment mortgages gradually pay off the loan balance. Interest-only mortgages only cover the interest during the term, so the capital still needs to be repaid later.

Do overpayments help?

Yes. Even small monthly overpayments can reduce total interest and shorten the time needed to clear the mortgage, depending on lender rules.

Does this include fees or stamp duty?

No. This calculator focuses on the mortgage itself. It does not include lender fees, legal fees, insurance, or UK stamp duty calculations.

Tool Info

Last updated:

Updates may include formula refinements, accessibility improvements, UI polishing, and additional mortgage planning options.