By contrast, she writes, if you increase payments to repay the loan in 10 years, you would pay $199,348 in interest – a saving of $495,681. It doesn’t have to start big. Pay fortnightly, and you can shave five years off your loan. Saving $150 a week on the grocery bill and putting it on the mortgage could take off 10 years and more than $250,000 in interest. Stop sending $40 a week on takeaways and that’s two years off the mortgage and $60,000 saved in interest. It won’t be easy but it can be done. Just start, Bird says.