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Our mortgage calculators

Whether you’re saving for your first home, budgeting for your next, or looking to save some money on your existing mortgage, our calculators are here to help.

  • Loans

    How much can I borrow?

    Find out how much you might be able to borrow based on your income

  • Mortgage

    Repayment calculator

    Find out how much your mortgage payments are likely to be

  • New-Home

    Stamp Duty calculator

    Find out how much you could save on stamp duty after the latest changes

  • Laptop

    Overpayment calculator

    Find out how much you might save by making overpayments on your mortgage

  • bank

    Base Rate calculator

    Find out how changes to the Bank of England base rate might affect your mortgage repayments

What is a mortgage calculator?

A mortgage calculator is a useful tool to help you determine how much a mortgage deal will come to cost you in the long run. With many different factors to take into consideration that may have an impact on the overall amount, trying to work out how much you’ll need to pay over your mortgage term can be an arithmetic challenge.

With a mortgage calculator, all you need to do is just enter some key information, such as the amount you’re hoping to borrow, mortgage term, and the interest rate. MoneySuperMarket’s free mortgage calculators will take care of the maths, providing you with a clearer picture of what you can expect.

We offer different types of mortgage calculators that are specific to what you want to discover. For instance, our repayment calculator can tell you how much your monthly instalments will amount to, depending on your loan size, repayment term, and interest rate. Or, with our overpayment calculator, you can learn how much you could save when adding extra cash to your instalments.

How is a mortgage calculated?

Your mortgage calculations depend on a number of different factors. Mortgages, as well as their repayments, will vary based on how much you decide to borrow, the length of your term, the type of mortgage you choose, and your interest rate.

But these are not the only things to determine your overall mortgage expenses. Remember that lenders will want to look at your credit score and history, as well as your personal expenses and outgoings. These will have an impact on how your mortgage and monthly instalments are calculated too.

By using a MoneySuperMarket mortgage calculator, you can find out how additional personal costs (e.g. child maintenance, existing loans, credit cards, etc.) can alter the costs of running your home and paying back your debt. Our mortgage calculators are also handy tools that allow you to consciously compare deals and pick the one that best suits your needs and budget.

calculator and pen

What type of mortgage can I get?

When looking for a mortgage to fund the purchase of your new property, you will be presented with several different alternatives.

Here are some of the most prominent mortgages you can go for:

  • 1

    Fixed-rate mortgage

    Fixed-rate mortgages have an interest rate that remains the same for a set period. Generally, it is anything between two to five years, but you can also find fixed-term options of up to ten years or more. With fixed-rate mortgages, you’ll know how much you need to pay each month (as your repayments are fixed), regardless of any rise in interest rates.

  • 2

    Variable-rate mortgage

    With variable-rate mortgages, your monthly costs could change throughout your loan term. This is because the interest rate changes in line with the Bank of England’s base rate. For standard variable-rate (SVR) mortgages, each lender has an SVR that they can move when they like. SVRs can be anything from two to five percentage points above the base rate (or higher).

  • 3

    Discount mortgage

    Rather than being linked to the Bank of England base rate, discount mortgages are linked to the lender's standard variable rate (SVR). For example, if the SVR is 4.50% with a discount of 1%, the payable mortgage rate is 3.50%. If the SVR rose to 5.50%, the pay rate would rise to 4.50%. Bear in mind that SVR changes are always at the lender’s discretion.

  • 4

    Interest-only mortgage

    With an interest-only mortgage, you only pay the interest charges on your loan. This means your monthly payments will be cheaper than on a repayment mortgage. However, at the end of your mortgage term, you’ll still owe the lender the amount you borrowed at the start. You can usually pay off your debt with savings or by selling your house.

  • 5


    Remortgaging is when you change your existing mortgage deal, whether that’s switching to a new lender or moving to a different rate with your existing lender. As well as being a good way of finding better interest rates and mortgage terms, it also lets you release equity from your property.

How to save for a deposit

As you search for a new home, it’s always wise to start saving money for a deposit. In fact, in most cases, banks and lenders will expect you to pay a deposit as an assurance or security on the mortgage they lend you. 100% mortgages, which is when you borrow the full value of the property and have no cash deposit, are rare. The only scenario where you might be able to borrow the full amount is through a guarantor mortgage.

This may sound daunting at first, especially if you’re a first-time buyer. Nevertheless, there are several ways in which you can put aside some money to get on the property ladder. For instance, you can set up a direct debit into your savings account. This way, you can deposit a fixed amount of cash each month into an account that you are less likely to use.

Try to assess your living situation, too. If your existing rent is too expensive to allow you to save money for a mortgage, you may want to consider opting for a flat share or moving back in with your parents for a while, if possible.

Figure out your mortgage expenses with MoneySuperMarket

Using a mortgage comparison tool can help you get a good idea of the kind of mortgage deals available. When you enter your information into MoneySuperMarket’s mortgage comparison tool, you’ll be able to compare example mortgage quotes from different providers.

Just tell us a bit about yourself, your financial situation, and your plans. We’ll help you scour the market in search of the mortgage deal that is right for your pockets and requirements. Then, feel free to use our online mortgage calculators to find out how much each deal would cost you overall.

woman looking at MoneySuperMarket website on a laptop

It is completely up to you. However, it’s always important to consider how much you can afford and borrow an amount you feel comfortable with. In fact, if you fail to stick to your mortgage repayments, you may incur fines. In a worst-case scenario, you may even risk having your home repossessed.

Also, there are other important factors you may want to take into account. Your personal situation could change in the future, as you may start a family, take a career break, or find a new job in a completely different field. All these aspects could have an impact in the long run on whether you will be able to cover heftier mortgage debt.

Don’t worry, the answer is no. We won’t perform any credit checks if you use our mortgage calculators. In fact, you’re not even asked to insert your name, as it simply uses some mortgage-related information to give you a rough idea of how much you could borrow.

Lenders will perform a full credit check only when you’re ready to apply for a mortgage. Bear in mind that this will be marked on your credit file.

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