-
Worked it out at 18 years (my mortgage period) and 2.25%.
Overpaying £500 a month would save interest of ~ £15k (and mean that the mortgage was paid off in 11.5 years).
Investing £500 a month at 5% compounding for 11.5 years would generate interest of ~£24.5k.
I've just discovered that this spreadsheet has a nice option for comparing savings to overpayments http://www.locostfireblade.co.uk/Downloads/MortgageSpreadsheet/Mortgage%20Schedule%20Calculator.xls
Am I missing something?
Did you work it out with compounding mortgage interest?
ie. the 2% over 25 years.