Home Mortgages Mortgage calculators & tools Offset Mortgage calculator

Offset Mortgage calculator

With an Offset Mortgage we’ll take your savings into account when working out your interest. Say you have a mortgage of £100k and £20k in savings. You’ll only pay interest on the difference – which in this case is £80k. Enter your details below to see how much an Offset Mortgage could save you in interest payments.

Your mortgage details

Your mortgage details

What could you save by Offsetting

What could you save by Offsetting

could save you
per month
which is
over the term of your mortgage.

The benefits of Offsetting


Offsetting monthly payment
Offsetting total interest payable

Without Offsetting

Without Offsetting monthly payment
Without Offsetting total interest payable

How we calculate these savings

  • the calculator assumes your interest rate will stay the same for the term of your mortgage
  • we’ve evened out the months so they’re all the same length – 30.4 days each – so monthly interest will be consistent
  • repayments are rounded up or down to the nearest pound
  • we’ve rounded time saved down to the closest month
  • interest is calculated daily and added monthly
  • interest saved is rounded up or down to the nearest pound
  • the calculator assumes the total savings balance is held in a linked account(s) and remains constant throughout the term of the mortgage
  • if your total savings increase or decrease on an adhoc basis, your monthly interest payments will also change respectively.

Please note – the information here is for illustrative purposes only and isn’t a precise calculation. This information doesn’t include all of the details you need to either make an overpayment or choose a mortgage. Make sure you read the separate Mortgage Illustration before you choose a mortgage.

Find the mortgage for you

Think carefully before securing other debts against your home. Your home may be repossessed if you do not keep up repayments on your mortgage.

Contact us

If you want to:

Move house, remortgage, discuss rates or borrow more

New to first direct

0800 48 24 48

Existing first direct customers:

03 456 100 103

If you have:

Completion questions, payment changes, statement requests, or to pay off your mortgage

03 456 100 198

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