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Lump sum repayment calculator

Use our simple lump sum repayment calculator to work out how much you can save by making a lump sum repayment on your home loan.

Our lump sum repayment calculator can help you work out how much money you can save by adding extra lump sums to your repayments. An extra repayment can also reduce your loan term, so you own your home sooner.

Here's how it works. If you make a large, one-off extra repayment (a lump sum) to your mortgage, you are reducing the principal amount of debt. This means you end up paying less interest in the long run, too.

Our lump sum repayment calculator is an easy tool that lets you estimate how much a lump sum repayment can save you in time and interest.

How to use the lump sum repayment calculator

In order to use a lump sum calculator, you’ll need the following details:

  • Your loan amount. This is the amount of money you borrowed.
  • The loan term. This is the length of your home loan. Most Australians choose between 20 and 30-year loan terms.
  • The interest rate. The loan's interest rate affects how much interest you pay every month.
  • The repayment frequency. Repayments can be weekly, fortnightly, or monthly, depending upon your agreement with your lender.
  • Lump sump repayment. Enter the single amount you wish to add to the loan as a lump sum repayment.
  • Lump sum made at year. This refers to when you make the lump sum repayment. If you're 2 years into your loan, select 2 years.

Once you input all of the necessary information into the calculator you'll be able to see the results right away and figure out if putting a lump sum toward your mortgage will be worth it in terms of savings. Usually a lump sum payment will go toward your principal more so than interest, which will help you pay down your loan faster than just making general repayments.

Example: Susan's lump sum repayment

Susan just inherited $10,000 unexpectedly. She decides to pay it as a lump sum toward her mortgage. In order to figure out exactly what a lump sum will do for her mortgage she uses a lump sum calculator.

Susan inputs her:

  • Original loan amount: $300,000
  • Interest rate: 3.0%
  • Loan term (30 years) and her repayment frequency (monthly)

Susan then inputs her lump sum information. She is looking to put down $10,000 and has already had her mortgage for 2 years. If she were to put a lump sum of $10,000 toward her loan, she'll save $12,654 in interest and take 1 year and 5 months off her loan.

Her monthly repayments are currently $1,265. This means Susan won't have to pay her mortgage repayment for 17 months, which is $21,505 in total, back in her pocket. Not a bad return for a $10,000 lump sum payment!

* This is a fictional, but realistic, example.

An alternative to making a lump sum repayment is an offset account

If you have come into a large sum of money, you don't have to throw it straight into your home loan. If your home loan has an offset account, you save the money in the account and you'll enjoy a similar benefit to the lump sum repayment but with greater flexibility.

An offset account is a bank account connected to your home loan. Any money that you save in it temporarily reduces (or offsets) your loan principal. This means your repayments stay the same, but you're paying less interest and so you pay off the whole loan faster.

This is the same benefit as a lump sum repayment but with a huge difference. Once you pay the lump sum into your home loan, it's gone. Your lender may let you access some of it via a redraw facility but it's their money now.

With an offset account you still retain total control over the cash while receiving the same benefit. So if you suddenly need some money to cover an urgent expense, it's right there. It's the best of both worlds.

However, if your loan doesn't have an offset account and you're confident you won't need the lump sum again any time soon, then simply throwing it into your home loan is not a bad idea. Getting out of debt faster is always wise.

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2 Responses

    Default Gravatar
    garethJuly 8, 2013

    hi, we are about to receive a 100k lump sum we have two home loans on the one property 213k at 5.45% and 129k at 5.69% also a 7k personnel loan at 16.4%. into which loan(s) should we place the money

      ShirleyJuly 9, 2013Finder

      Hi Gareth,

      Thanks for your comment.

      Since is a comparison website we’re not licensed to give any personalised financial advice. You may want to consider speaking to a financial advisor.


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