By overpaying £50 a month on a 25-year mortgage of £100,000 with an interest rate of 4.99 per cent, would save you £12,217.85 and shave three and a half years off your mortgage term.
By doubling that overpayment to £100 you would save £20,864.25 and shave six years off the term.
Use our overpayment calculator to find out how much you will pay