How to Use the Mortgage Calculator
Enter your property price, deposit amount (in pounds or as a percentage), your expected interest rate, and your chosen mortgage term in years. The calculator will instantly show your monthly repayment amount, total interest payable, and total amount repaid.
You can toggle between entering your deposit as a fixed amount (£) or as a percentage of the property price. The calculator automatically updates the Loan-to-Value (LTV) ratio, which is important for determining the mortgage rates available to you.
Understanding Your Monthly Mortgage Payment
Your monthly mortgage payment is made up of two components: interest and capital repayment. In the early years of your mortgage, the majority of each monthly payment goes towards paying interest. As the years progress and the outstanding balance reduces, a greater proportion of each payment goes towards reducing the capital.
This is clearly illustrated in the amortisation chart below the calculator. The blue line shows your remaining mortgage balance declining over time, while the amber line shows the cumulative interest you have paid.
UK Mortgage Interest Rates in 2025
As of 2025, UK mortgage rates for a 2-year fixed deal typically range from around 4.5% to 6%, depending on your LTV, credit history, and the lender. Five-year fixed rates tend to be slightly different, reflecting the lender's view on future interest rate movements.
The Bank of England base rate directly influences tracker mortgages and standard variable rates (SVRs). Fixed rate mortgages offer protection from rate rises during the fixed period but may have early repayment charges (ERCs) if you want to exit early.
Use the interest rate slider to model different scenarios — for example, what would your payment be if rates rose to 7% or fell to 4%? This stress-testing exercise is important for ensuring your mortgage remains affordable in different economic conditions.
Loan-to-Value (LTV) and Mortgage Rates
Your Loan-to-Value (LTV) ratio is the size of your mortgage as a percentage of the property's value. A lower LTV means less risk for the lender and, therefore, access to better interest rates. Here are the key LTV thresholds to be aware of:
- 60% LTV or below: Access to the very best rates on the market
- 75% LTV: Good rate tier — widely available from most lenders
- 80%–85% LTV: Rates start to increase noticeably
- 85%–90% LTV: Higher rate tier — fewer lenders available
- 90%–95% LTV: Limited lenders, significantly higher rates
Mortgage Term: How Long Should You Fix For?
The standard UK mortgage term is 25 years, but this has been increasing. Many first-time buyers now take 30 or even 35-year terms to keep monthly payments manageable on a tight budget. While longer terms reduce monthly costs, they significantly increase the total amount of interest paid over the lifetime of the mortgage.
For example, on a £200,000 mortgage at 5.5% interest:
- 20-year term: £1,376/month, £130,000 total interest
- 25-year term: £1,228/month, £168,000 total interest
- 30-year term: £1,136/month, £209,000 total interest
You can use the overpayment calculator to see how making regular overpayments can significantly reduce your term and the total interest paid.
Other Costs to Consider When Buying
Your monthly mortgage payment is just one of the costs of home ownership. Other key costs to budget for include:
- Stamp duty: Use our stamp duty calculator
- Solicitor/conveyancing fees: Typically £1,000–£2,000
- Survey costs: £300–£1,500 depending on type
- Mortgage arrangement fee: £500–£2,000 (some are fee-free)
- Buildings and contents insurance: From around £150/year
- Life insurance / critical illness cover: Protects your mortgage if you cannot work
- Removal costs: £300–£2,000 depending on distance and volume