Mortgage calculator: how much will my mortgage go up?

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Man with house and calculator in background

Mortgage interest rates have risen sharply over the past six months after years of historic lows.

As higher interest rates will mean higher mortgage payments, experts say more people are at risk of falling into debt or losing their homes.

Try our calculator below to see how your fixed rate mortgage might be affected as borrowing becomes more expensive.

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About the data

This mortgage calculator uses a standard mortgage repayment formula to estimate the monthly payments or interest rate based on the amount borrowed and the length of a mortgage.

The calculator assumes a single, fixed, interest rate which stays the same over the term of the mortgage and interest is charged monthly.

Why is my monthly payment estimate different to what I actually pay?

This might be down to:

  • Other payments included in your monthly payment, such as insurance
  • Mortgage fees being included in your total mortgage borrowing
  • The length of your mortgage. The calculator only works for mortgage terms of full years

If there is a difference you can enter your current monthly payment instead of the interest rate.

What if I have a variable rate mortgage?

This calculator assumes that the interest rate stays the same over the term of the mortgage so is not suitable for variable rate mortgages.

What if I have an interest only mortgage?

This calculator only works for repayment mortgages.

What if I have more than one mortgage?

This calculator only works for a single mortgage at a time.

What if I don't know what my interest rate or monthly payments are or would be?

You can use mortgage comparison tools on official mortgage lender's websites to see what a likely interest rate or monthly payment would be for the amount you were looking to borrow.

What are the values already in the calculator based on?

  • How much are you looking to borrow?

The value of £160,000 is based on the average outstanding balance for a fixed rate mortgage as of June 2022, according to UK Finance.

  • How long will you take to pay it back?

The value of 20 years is based on the average outstanding term for a fixed rate mortgage as of June 2022, according to UK Finance.

  • What is your current interest rate?

The value of 2% is based on the average interest rate for outstanding fixed rate mortgages as of June 2022, according to UK Finance.

  • What is your current monthly payment?

The value of £809 is based on the estimated payments made at 2% based on a mortgage of £160,000 over 20 years.

  • Interest rate to compare against

The value of 5.8% is based on research from moneyfactscompare.co.uk from 5 January 2024, who reported this figure as the average rate for a new two-year fixed rate loan.

Produced by: Alexandra Nicolaides, Libby Rogers, Becky Rush, Jana Tauschinski, Rob England, Alexander Ivanov, Mark Oludimu and Scott Jarvis