Offset calculator

Get a better understanding of the potential savings that your client could make by offsetting their savings against their mortgage.

To tailor the results to your clients circumstances move the sliders below.


With an Offset account, mortgage interest is only calculated on the difference between the two balances.

Graph options
Your mortgage

Show months

Mortgage Term
Your Savings

To get started, adjust the sliders on the left

Mortgage balance (£)

Estimated monthly repayment (£)


Based on the information provided, an illustration of the possible benefits of offsetting:

a monthly repayment of:


could pay off your mortgage in:


giving interest savings of:


and a tax saving of:


Based on the information provided, an illustration of the possible benefits of offsetting:

A reduced monthly repayment of:


Could pay off your mortgage in:


Please note

The calculations used in the demonstrator are for illustration purposes only and assume the following:

  • The interest rate will remain the same throughout the term of the mortgage - our actual mortgage rates available are dependent on market conditions so change from time to time.
  • Requires a static (i.e. fixed) payment to be set up and maintained throughout the mortgage term.
  • The mortgage repayment method is capital and interest.
  • No interest is payable on the Offset savings balance.
  • Regular monthly savings deposits are made throughout the mortgage term (in line with the 'Monthly Savings Deposit' entered), or a constant savings balance is maintained (in line with the 'Current Savings Balance' entered).
  • You make a lump sum deposit into your linked Offset savings account of the amount specified above and that you maintain this balance.
  • The example used on this page assumes that basic and higher rate tax payers do not pay tax on their savings and that additional rate taxpayers pay 45% tax on savings interest and are based on current HM Revenue and Customs rules which are subject to change. Customer usage of any applicable Personal Savings Allowance is not included within these calculations.
  • *AER stands for Annual Equivalent Rate and shows you what the interest rate would be if interest was paid and added each year. This will enable you to compare more easily the return you can expect from your savings over time.

For more information on Offset payment options please refer to our offset option guide.